I agree with you, normally im a very point blank person. we had this argument years ago where I told her in no uncertain terms how ridiculous she was (long story short, I lived with my brother and she threw a Batchelorette party at our house and had her guests sleep in my room while I was out of the country (without asking me). 6k worth of my best jewelry went missing and I fb'd the person who I thought did it, not yelling, but telling them I forgave them and making sure she knew the diamond grades in case she sold them. What would kill me was not that they were missing, but The idea of them being pawned for $50. SIL was angry i didn't tell her i was going to send the message before i did, that girl of course denied it. The jewelry showed up inexplicably 2 months later underneath toilet paper rolls in a cabinet at my mother's house. Mystery to this day. She still hasn't forgiven me even though I've apologized multiple times, written the friend an apology topthe friend, then gave away the fucking jewelry because everyone was so upset. it's a sore topic and my brother has told me it's the cause of our rift.
I usually don't have any overly sensitive friends, because I feel like a bull in a China shop.. no one knows why the bull is breaking the China though. Maybe he needs room and feels clasterphobic by fragile things too close, maybe he wants to break them all at once so he doesn't have to do it one by one. Or maybe he's oblivious to it all and is just being him. I've hurt people by being blunt (knowingly and unknowingly for all those reasons).
Anyways, I want a good relationship with my SIL. I want all the things she told me she wanted before she got married. I've taken her out to dinner multiple times, extra thoughtful and expensive gifts at holidays.. I've repeatedly invited her to hang out, made an effort to learn a hobby of hers (quilting), and I've got fucking nothing to show for it. I at least want to be civil and I don't understand the animosity. She thinks I 'ruined the relationship' with her friend over the jewelry incident because 'she had to side with and support me, her sister'. It's not like I called her friend a thieving bitch, i just told her the value and that I forgave her if she did it and then I profusely apologized when the jewelry was found. The friend basically told me 'is fine, but it's not fine.' As If we were fucking desperate housewives.
I don't think the relationship with SIL is beyond repair, but I don't know if there's anything more I can do. I'm worried she'll divorce my brother some day..