sil in wedding???

You shouldn't have anyone in your bridal party that you don't want in it and uneven sides in the bridal party are okay too

Nope. You only want two. You are not required to have your SIL in your wedding. At Christmas my brother came up to me in front of everyone and said that he and SIL were talking and she told him that she wanted to be a BM, but that she couldn’t ask me. So he took it upon himself to ask me if his wife could be a BM. Ummmm, no. I really like her, but we’re not close. We went six months without talking or texting at all so why would she think I would have her as a BM. She didn’t have me as a BM for her, I was a reader, and even if I had been a BM like you were for your SIL, that doesn’t automatically make someone a BM for you. Keep your wedding party with the 2 BM you want.

As a SIL who was not a part of a wedding and really not included at all, I can tell you it was pretty hurtful. That said it’s your special day and you shouldn’t do anything just to please someone else or anything you don’t really want to!