From what I have read, it seems your wife is probably just concerned with you getting to bed at 2-3am and than having to get up a few hours later for work. She is probably worried you will burn yourself out.
Lets face it, you "both" have very long days with you working and her taking care of the baby and your home. She probably wants you to get enough rest to handle everything which is why she tries to get to bed early.
I "dont" think she is being selfish. I also "dont" think you are being selfish either. Everyone needs "their time" no matter who you are. Maybe just have "your time" before 2-3am and than everyone will be happy. Just my thoughts.
I'm sure you will find a happy medium together.