After bending over backwards last month for my Brother and his wife's Sealing (they're active LDS/Mormon and did a civil ceremony last year and got Sealed in the Mormon Temple for their 1 year anniversary), my SIL has started making life a little difficult. I took their announcement pictures for free, baked over 10 dozen cookies the night before because she decided at 11 PM that she NEEDED them, set her up with a professional photographer friend for next to nothing ($200 which is beyond cheap for a pro), and my FH and I set up the reception including hauling all the food there ... and we never even got a thank you from her. My FH & I got engaged a few days before their reception but didn't make a big deal out of it until after their reception so we wouldn't steal their thunder. She's been nothing but catty lately when it comes to anything wedding related - especially when she found out she's not a bridesmaid. My brother is one of my best friends and a groomsman & she's driving a wedge!
My mom suggested including her on more things to ease the tension but I don't know how to include her so she doesn't get even more ticked at me but still keep her as a very minimal role so she won't ruin my happy love bubble lol. She went dress shopping with me once but refused to go again when I got the dress (she told my sister that she felt that she had done more for me than one of my Co-MOHs and that it was insulting to be there with her when she wasn't even an attendant). And I have asked her to help me make a flower girl tutu for my niece. But she still feels left out and is acting bitter.