S.E.
First of all, she's only 3 and some kids don't totally get it until 5. Secondly, you just had a baby!! Kids react in all kinds of ways to new siblings, and this may be her way to get your attention or just still be a baby like the cute new competition. I would definitely STOP making a big deal of it. I know that's easier said than done and with an infant to take care of, you'd like to be done with potty training. But it sounds like she knows it's her power card with you, that you want her to do this one thing so badly. Usually when you stop caring, so will she, and viola, she just may start using the potty because it's nicer for her that way, too. If she is getting up from bedtime and naps with wet diapers, that tells you her body doesn't wake her up to go, so she's not quite ready for total potty training anyway. I'd just let whatever happens happen for the next couple weeks - no pressure from you, praise when she does a good job, neutral when she doesn't. Then, introduce Pull-Ups since she's getting to be such a big girl! And pretty new undies! And let her progress at her own speed. It really will happen, at her pace. Good luck!