Bridesmaid vs Reader

I think that you should consider the sister-in-law you are closest with to be your bridesmaid. If you feel you have a better relationship with her and want to include someone from your FH's side of the fam, then that's how the decision would be based off of.

Including the second sister in law as a reader is perfectly fine. She will still be involved in some way. The only complication I see is if this second sister in law is not reasonable or understanding for the reasons why you would give so and so this and that part in your wedding. If so, then you may have to talk it out if they do see some wrong in it.

In the end, it is your decision since you know how these people will react. But yeah, that's my two cents.

Best wishes and I hope it resolves well!

I honestly think that asking someone to be a reader just means - you're not important enough to be a bridesmaid but I wanted to include you so here. Which, yes, that would probably hurt someone's feelings. The only time I feel like it is acceptable is if you aren't close due to a big age gap. Someone 10+ years older than you probably won't really want to be a bridesmaid but would feel honored to do a reading.

I wouldn't ask the other SIL to be a reader. Just have the one you're closest to in your bridal party as planned

I personally would just ask both of them because i would feel really uncomfortable choosing one over the other even if i'm closer with one. There's no right or wrong really, but that's what i would feel more comfortable doing.