@veritek33, congrats!! Lovely ring!
I didn’t know this until recently, because the weddings happened before I entered my fiance’s life, but one of his sisters had a wedding planned and the other then got married a few weeks before the first sister. The first sister who had the wedding planned first was annoyed. So I can somewhat understand your SIL’s annoyance. EXCEPT that you ran it by her and she said she was fine with it. She should’ve said something like “I’d probably be having a shower around that time, everyone will be busy with last minute details, etc.” but maybe she figured it would be rude to say that. At any rate, I’d also consider moving it up sooner – not sure when in 2020 you’re thinking, but my engagement is 7 months long and it seems like such a long time to be worried about all the wedding details. Better to pack it into a shorter time, in my opinion!