almost 3 yo seems to need less sleep than recommended - but I'm pregnant
I think it's normal that not every child needs as much sleep as others. I wouldn't worry too much unless it was affecting behaviour or there were other signs pointing to an issue.
There are lots of things to try, a childproof room for her to play in while you snooze on the couch. Putting her to bed when you are ready to do and getting her to read books or play quietly until you are ready to get up. Having healthy and easy to reach snacks for her to grab while you are napping/snoozing/sleeping. Have a quiet time box or daily quiet time boxes so that she has something completely different to play/with do at "quiet" time instead of nap time. This allows you to get a nap or when the baby comes allows rest time without a nap at the same time that the baby has it's biggest nap and you can also get some quiet/rest time.