I don’t know about the specific prayers you are talking about, but if I understand that they are in focused on petitioning the infant Jesus in prayer, I see no problem with this.
After all, didn’t John leap in the womb (a form of prayer? Rejoicing? Maybe…

when Mary, entered the room with the baby Jesus peaceful inside her womb?
And, as catholics accept the teaching of the Eucharist, you see in that the fragileness of an infant. Something to be held tenderly with love. As parents must prepare for a newborn, those who recieve the Eucharist must also be prepared to partake, or take in this fragile Jesus.
Remember also how the shephards who saw him right after birth, were so amazed by what they saw.
As a baby, before he was born as legend has it, 3 kings tried to find this King, they knew would come as a baby. They were not put off by his coming to the world in a manger. They brought to him gifts, they did not give up his location to his would be killer.
A baby, yes. When I held mine in my arms for the first time, that was the beginning of the chipping away of my resisting God. God came first to me in this way, even though I did not fully realize it until recently. But, looking back- that was the very day he started to let me know him.