My one thought if you were to go ahead with are “hours of operation”.
I am a knitter/crocheter and love to frequent “Local Yarn Shops” which tend to be boutiquey and I also love to check out local tack stores that I don’t know.
My biggest complaint is common for both, the hours of operation often preclude my patronage. I tend to work 9-5/6ish… and alot of these places close at 6 during the week. Hard to spend the money if you can’t make it in.
Love the idea of doing a small section in your sister’s store to start off and really recommend having an awesome website. Even if you don’t sell directly from it, I often like to see what there is to see if a trip in is even worth it.