I think the most obvious threat is the one being overlooked:
Ralph has threatened to take Rozy.
In the case with Faith, he wasn't part of the child's life before Xander was born, nor was he on the birth certificate. He was also facing criminal charges stemming from a targeted attack on his son's mother.
In Rozy's case, he was on the birth certificate and has been part of the child's life since day 1. He's been the sole provider since Rozy was born due to May being in college and will claim a lot of other things. While he would never could get full custody, leaving Rozy with him even 1 day a week is more than a horrible idea, it's child endangerment. May knows this. Realistically between Harry's resources, NY and US laws, etc. May will eventually be able to gain near, if not full custody but it will be a process.