The only information I could find in English language sources is in Emile Bougaud, The History of St. Monica. New York: P. J. Kenedy 1885. Bougaud (1823-1888) was a French cleric who ultimately rose to the position of Bishop of Laval. The English edition is a translation by Rev. Anthony Farley of Abbé Bougaud, Histoire de sainte Monique. Paris, Vve Poussielgue et fils, 1866, 2e édition. The miracles enumerated in the book seem to generally pertain to the instant healing of various health afflictions.
On pp. 340-342, there is the following description of miracles that occurred as the carriage with the remains of the saint entered Rome prior to Palm Sunday 1430:
And now a miracle augmented the enthusiasm. A woman, with a sick child in her arms, hurried up through the crowd, which instinctively made way for her. She approached the shrine wherein were deposited the mortal remains of the Saint, and touched it with her sick child, while her face revealed the intensity of her faith. Suddenly a great shudder of awe ran through the vast multitude; the child was healed
Another miracle of the same nature, but even more striking, revealed the greatness of St. Monica, and taught what were the special graces that might be expected through her powerful intercession. A mother was watching at the bedside of her son, who had been afflicted with a hopeless malady for about eight months. She learned what was passing, and in obedience to one of those impulses of faith and indomitable hope, such as influence the heart of a mother, she took her sick child in her arms, and wrapping it up, carried and deposited it on the coffin of St. Monica, then stood at the foot, with heart full of faith, expecting St. Monica to manifest herself a true mother to her dying child. She had not to wait long; the child soon rises and throws himself into his mother's arm, joyous and healed.
Many other miracles marked the translation of St. Monica's relics from Ostia to Rome. These will be enumerated later on by Pope Martin V. We will note only one fact of great significance and exquisite delicacy. Besides the children cured in the arms of their mothers, it is remarkable that the most frequent miracles were the restoring of sight to the blind.
This information is apparently extracted from a papal sermon in honor of Saint Monica that is reproduced in an appendix "Sermon Martini Quinti Romani Pontificis in Honore Sanctae Monicae" at the back of the book. But no specific reference as to the source (such as a manuscript in the Vatican Library) is provided. Bougaud also mentions (p. 351) a Papal Bull given at Rome on April 27, 1430 (eleven days after Easter and thus eighteen days after Palm Sunday), but it is not clear how it relates to the sermon.
From what I can tell with my rusty knowledge of Latin, Bougaud seems to have embellished the scene on entry of the relics into Rome a bit. The Latin text first mentions a feeble man approaching the procession, venerating the saint. He is healed overnight of leprosy-like blemishes. Then along the way another man, almost blind, whose sight is restored after prayer. Followed by a mother with a sick child with a diseased eye who bows in prayer before the body of the saint. The child is healed, its sight restored:
Puerulus erat in domo Fratrum, Frater altero oculo derelictus. Hunc mulier cognata avitum applicavit, ut ante Corpus aliquid pueriliter orans flecteretur: atque illa cum paucis mulieribus pueri valetudinem precata, paulo post surgens, sanum atque integrum utroque lumine recepit.
Finally a second mother who places her child, afflicted with a grave illness for eight month, on the coffin ("in the Ark"). It is healed and rises on its feet:
Mulier cuius filius erat octavum iam mensem gravi atque implicito morbo aegrotus, arreptum parvulum sincerissima spe, in Arcam imponit: mos sanum factum, super pedes nitentem iam infantulum statuit.
A second section of the sermon describes a different set of miracles that occurred in the few days between the arrival of the saint's remains in Rome and the delivery of the sermon.
Mulierem nomine Silviam ex intolerabili dolore capitis, facto voto, continuo liberatam. Mariolam aliam vestri Fratris sororem iam tumore mamillarum una et maxima febri morti pene vicinam, tactu Sepulcri mox sanatum. Puerum illum sumto toxico morientem, a parentibus huic Sanctae non prius commendatum, quam sanatum. Aliam nobilem Romanam simul et paralyticam etmorbo comitiali, quem caducum appellant, vexatam, tacto Sepulcro, mox ad integram sanitatem restitutam. [...]
The English translation of this can be found on p. 349
A woman named Silvia was greatly tormented by a violent pain in her head. She had recourse to the intercession of our Saint, and was instantly relieved. Another, called Mariola, sister of one of our brethren was suffering from a cancer in the breast. By touching the Saint's tomb she was instantly cured and freed from a raging fever that had almost brought her to death's door. A little child had swallowed poison and was about dying. Hardly had its parents recommended it to the Saint when it was cured. A noble Roman lady, afflicted with paralysis and the falling sickness, or epilepsy, was immediately cured by touching the tomb. [...]
Gillian Clark, "Monica - An Ordinary Saint", Oxford University Press 2015, p. 168, provides the following context for the sermon given by pope Martin V:
By the time Gozzoli painted his sequence of frescoes, there had been a further discovery of relics at Ostia [...] The Hermits were given permission to move these bones to San Trionfe, their church in Rome. The "translation"
(literally "carrying across"), a technical term for moving the body of a saint) took place on Palm Sunday in 1430, and was reported by Andrea Biglia, an Augustinian friar. Monica was not a new saint, so there was no need for
formal "canonization" [...] But Biglia ascribed to Pope Martin V a sermon, preached to the Hermits, in which it was said that people had not known the name of Monica, but when they realized who she was they rushed to be near her, and healing miracles accompanied the translation.