My grandchildren were not baptized and I was worried about it. They are going on a trip. Therefore, I took it upon myself to baptize them. What if anything is the Catholic Church's view of this? My children are not practicing Catholics. When my oldest grandson was a baby, maybe about six months old, I was giving him a bath in the kitchen sink and poured water over him and stated specifically, "In the name of the Father, the Son, and the Holy Spirit"... I did this to the other four today. I told my son and daughter. My daughter just chuckled and my son was upset with me. They were raised Catholic and went to Catholic school, but neither are practicing now.
Canon law states:
§1 For an infant to be baptised lawfully it is required:
1° that the parents, or at least one of them, or the person who lawfully holds their place, give their consent;
2° that there be a well-founded hope that the child will be brought up in the catholic religion. If such hope is truly lacking, the baptism is, in accordance with the provisions of particular law, to be deferred and the parents advised of the reason for this.
§2 An infant of catholic parents, indeed even of non-catholic parents, may in danger of death be baptised even if the parents are opposed to it.
Given that your grandchildren were not in imminent danger of death, it appears that your actions may have been in breach of canon law.
While the church makes allowances for baptisms in case of emergency, for this baptism to be valid (or ruled otherwise) it is required to consult with a local priest or the local bishop/bishop's office. Beyond the point that Dick Harfield makes regarding canon Law 868, wherein it is expressly the parent or legal guardian's role to baptize the children, there is this further consideration.
THE MINISTER OF BAPTISM
Can. 861 §1. The ordinary minister of baptism is a bishop, a presbyter, or a deacon, without prejudice to the prescript of ⇒ can. 530, n. 1.
§2. When an ordinary minister is absent or impeded, a catechist or another person designated for this function by the local ordinary, or in a case of necessity any person with the right intention, confers baptism licitly. Pastors of souls, especially the pastor of a parish, are to be concerned that the Christian faithful are taught the correct way to baptize.
> Can. 862 Except in a case of necessity, no one is permitted to confer baptism in the territory of another without the required permission, not even upon his own subjects.
Can. 878 If the baptism was not administered by the pastor or in his presence, the minister of baptism, whoever it is, must inform the pastor of the parish in which it was administered of the conferral of the baptism, so that he records the baptism according to the norm of ⇒ can. 877, §1.
By the way, your concern has arisen at our parish with some frequency by people with grandchildren. One of our deacon's indulged in considerable discourse on this last year. As he put it, the Church (in this diocese anyway) prefers to encourage the parents to return to "practicing" status from which baptism would follow logically. Catholics Come Home is one of a number of programs focused on that very issue (and a ministry he is active in).