Maternity leave

Just want another opinion from other moms- I’m having my baby in April and have been informed she will need to stay in the NICU for monitoring after birth due to a condition she has. they are unsure of how long her stay will need to be as it will all depend on baby when she gets here. She will also need a surgical procedure at some point shortly after birth/newborn stage. I was already granted a 12 week FMLA but am worried that I may need more time depending on how everything goes. I brought this up to HR and they told me that it would be considered a personal leave after 12 weeks which is fine. Do you think that it is too much for me to ask for more than 12 weeks off with my baby with this situation? Feeling a little guilty like they may think I’m milking it but I have no idea what to expect