I'd have a girls day with just you and her. Take her out to lunch and a manicure/pedicure. Those are always nice. Or if you know of something that she really wants wants buy it for her.
Go to "things remembered" and buy her a picture frame and have something very special written on it. That's what we did for hubby's grandma. And when I find the right frame we are getting his mom one that says "Our Grandchildren"
I like the ideas the other a have said. My only idea would maybe be some kind of spa day or something similar? Meal out?
I think she's being rude. You can't help who came to the party and if you did why at the moment would you cause drama at your party and force someone to leave. You didn't make her leave, she left on her own. I don't think you need to do anything special for someone who's trying to stress you out. As far as I'm concerned you don't even need to explain yourself. I'd just give it time and let her come around. You did all you could letting her know you didn't know she was going to be there. That's all you can do. Gong out and spending extra money you may not have on someone who's so quick to jump the gun, she may cause even more drama when you try and take her out. Just be careful with whatever you decide. Sorry you have to be so stressed. Good luck! ♡ :)
Send her a thank you basket with a card to tell her how thankful you are for her kindness. It dont have to be expensive but be thoughtful.
I would do a girls day with just her. Take her to lunch and tell her again how much you appreciate her. I think some one on one time will really show her how much you appreciate her. I hate that is going on between your sister and Aunt. Babies have away of changing people's hearts, so maybe when the baby is born they will both be over joyed and forgive each other. Good luck.
Her leaving the baby shower that she mostly planned for you was sortve rude A.either she was just avoiding because she didn't want to have any drama at your shower or b. Maybe she just felt uncomfortable ..but either way she should've stayed and enjoyed it with you and just try to be civil ...don't feel bad its not your fault if anyone out of this situation should feel bad its your sister and aunt you can't change the actions of others...personally I wouldn't do anything for her it was her own decision to leave she made that chose not you ...
I would obviously thank her for planning the shower but make it known that you kindve felt hurt that she didn't stay and enjoy it with you ..nothing wrong with expressing your feelings because obviously this is bugging you .. Good luck :)