The big announcement

Dee • My rainbow baby is due in Aug 2015 <3
Okay gals so I haven't told anyone in my family besides me fiancé and my sister that I'm pregnant. I want to tell me parents on Christmas but I'm still undecided. I plan on telling my whole family when I'm around 12 weeks to play it safe BUT I have one major issue. 
My soon to be sister in-law who I've recently had problems with due to I didn't make her my maid of honor and now it's the end of the world. She's pregnant and due in May. She told our closest family in person that she was pregnant without me or my fiancé there. We found out over Facebook! We always see her and talk to her and she had the decency of not telling us. It made us furious and what really pissed me off is she didn't tell her brother the one who's always there for her no matter what. 
So that being said I think she deserves to find out the same way. It was a very low and quite rude thing for her to do. 
So do I tell her when we tells everyone else or do I let her stay in the dark like we had to?