Catholic Foundational Teaching acknowledging Mary as "All-Holy" therefore an offense on the Blessed Virgin Mary is really and certainly classified as blasphemy.
493 The Fathers of the Eastern tradition call the Mother of God "the All-Holy" (Panagia), and celebrate her as "free from any stain of sin, as though fashioned by the Holy Spirit and formed as a new creature".138 By the grace of God Mary remained free of every personal sin her whole life long.
"Let it be done to me according to your word. . ."
721 Mary, the all-holy ever-virgin Mother of God, is the masterwork of the mission of the Son and the Spirit in the fullness of time. For the first time in the plan of salvation and because his Spirit had prepared her, the Father found the dwelling place where his Son and his Spirit could dwell among men. In this sense the Church's Tradition has often read the most beautiful texts on wisdom in relation to Mary.101 Mary is acclaimed and represented in the liturgy as the "Seat of Wisdom."
2030 It is in the Church, in communion with all the baptized, that the Christian fulfills his vocation. From the Church he receives the Word of God containing the teachings of "the law of Christ."72 From the Church he receives the grace of the sacraments that sustains him on the "way." From the Church he learns the example of holiness and recognizes its model and source in the all-holy Virgin Mary; he discerns it in the authentic witness of those who live it; he discovers it in the spiritual tradition and long history of the saints who have gone before him and whom the liturgy celebrates in the rhythms of the sanctoral cycle.
Therefore, based on the Catholic Church Teaching and Doctrines the Blessed Virgin Mary is "All-Holy" by virtue of God's singular priveleges and graces bestowed on Mother Mary for Her Mission in the Church as the Mother of the Redeemer and also the Mother of all the Redeemed.
With regards to the 5 five types of offenses and blasphemies committed against the Immaculate Heart of Mary as revealed to Sis.Lucia, this sin are not only blasphemy but described to as "unforgivable sin". This five offenses or five grave sins to the Theotokos cannot be forgiven by the Justice of God and requires reparation.Sis.Lucia describes why Mary reveals this five blasphemy in order for all the souls who committed this type of offenses rendered by God as the "unforgivable sin" can be appease and atone.
In 1929, in the apparition of Tuy which is the final fulfillment of Fatima, Our Lady will conclude the extraordinary manifestation of the Holy Trinity with these striking words: "So many are the souls which the justice of God condemns for sins committed against Me that I come to ask for Reparation. Sacrifice yourself for this intention and pray." These words are so strong that several translators took the liberty of diluting their meaning.
See, this five grave offenses are not only blasphemous but it is the "unforgivable sins".
"A little act of Reparation" to save the greatest sinners. Yes, Our Lady affirms sadly, many souls are lost because of their scorn, their blasphemies against Her . . . Thus, giving us the example of loving our enemies, She Herself intervenes, because She alone can still save these monsters of pride and ingratitude who have revolted against Her. As "Mother of Mercy and Mother of Pardon," as we sing in the Salve Mater, She intercedes for us before Her Son: may the filial devotion of faithful souls, and the Communions of Reparation offered on the Five First Saturdays to console Her outraged Heart, be accepted by Him in Reparation for the crimes of sinners. Our Lady prays that He deign to accept this "little devotion," and take into account this "little act of Reparation" to Her Immaculate Heart, and deign to grant pardon in spite of everything, to the ingrates and blasphemers, all the poor souls who have had the audacity to offend Her------She, His Most Holy Mother! The Fatima Crusader
The five revealed offenses to the Blessed Virgin Mary the "Mother of Mercy and Mother of Pardon" is unforgivable because Mary instead of punishing the souls who committed this sins simply "cried tears even tears of blood" in many of the approved Marian Apparitions.
The "cries of tears even tears of blood of the Theotokos" for all the souls condemned by the Justice of God moved the Sacred Heart of Jesus.The words of Jesus reveals to Sis,Lucia the following in order to console Her Mother's Sorrowful & Immaculate Heart.
"(Words of Jesus) See, My daughter, the motive for which the Immaculate Heart of Mary inspired Me to ask for this little Reparation, and in consideration of it, to move My mercy to pardon souls who have had the misfortune of offending Her. As for you, always seek by your prayers and sacrifices to move My mercy to pity for these poor souls."
Explanation on the Sins against the Holy Spirit:
"The sin against the Holy Spirit." Here we have one of the principal themes of the Message of Fatima: since God has decided to manifest more and more His great design of love, which is to grant all graces to men through the mediation of the Immaculate Virgin, it seems that their refusal to submit with docility to what God wills is the fault which most gravely wounds His Heart, and for which He no longer finds in Himself any inclination to pardon. This sin seems unforgivable, because for Our Savior there is no crime more unpardonable than to despise His Most Holy Mother, and "to outrage Her Immaculate Heart, which is the Sanctuary of the Holy Spirit. This is committing "the blasphemy against the Holy Spirit, which will not be forgiven in this world or in the next." The Fatima Crusader
The Justice of God condemned this sins because it is a direct offense to the Most Holy Trinity.
Mary is the chosen daughter of God whom God chooses in eternity to be dwelling place of the Logos and the Holy Spirit.
721 Mary, the all-holy ever-virgin Mother of God, is the masterwork of the mission of the Son and the Spirit in the fullness of time. For the first time in the plan of salvation and because his Spirit had prepared her, the Father found the "dwelling place" where his Son and his Spirit could dwell among men. In this sense the Church's Tradition has often read the most beautiful texts on wisdom in relation to Mary.101 Mary is acclaimed and represented in the liturgy as the "Seat of Wisdom."
In her, the "wonders of God" that the Spirit was to fulfill in Christ and the Church began to be manifested:
As the Book of Kings stated "the Highest Heavens cannot contain God whom She carried in Her Womb".
Panagia (Greek: Παναγία, fem. of panágios, pan- + hágios, the All-Holy; pronounced Greek pronunciation: [panaˈʝia]) in Medieval and Modern Greek, also transliterated Panayia or Panaghia, is one of the titles of Mary, the mother of Jesus, used especially in Eastern Catholicism and Orthodox Christianity.

The Wondrous Icon of Panagia Prodromitissa
Theological Support that the five offenses listed above against Mary is the "unforgivable sin".
Mary is acknowlege by Church Tradition as the Mother of Mercy and in Fatima Apparition Her direct and urgent message is repentance "Penance,Penance,Penance."
When a christian not only reject the calling of the Mother of Mercy the instruments used by God to call on all the Redeemed to repentance but instead commits any of the five grievious offenses. The Catechism of the Catholic Church defined it as the "unforgivable sin".
1864 "Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven."136 There are no limits to the mercy of God, but anyone who deliberately refuses to accept his mercy by repenting, rejects the forgiveness of his sins and the salvation offered by the Holy Spirit.137 Such hardness of heart can lead to final impenitence and eternal loss.
Mary is the Spouse of the Holy Spirit the instruments of God in calling all people to repentance as seen in the Fatima Apparition. Rejecting Mary the Mother of Mercy is rejecting the Holy Spirit actions thru Her Maternal Mediation imploring all souls to seek repentance.