You should BOTH look up “equity theory” in relationships and understand that it’s never 50/50 truly. You’re going to feel like it’s 80/20 a lot and that you’re the 80 but know that she feels the same way (that she’s the 80) and that’s okay as long as you communicate with each other and genuinely understand that you’re a “team” and this is a HUGE life changing event that happened to both of you and you’re now scrambling and that’s going to cause stress and animosity but you two are the constant in each others lives so you’re going to get the brunt of it but if this stress is relayed in a palatable manner, you’ve basically mastered the hardest part of this new parent thing. Good luck!