Old drama coming back up (sister in law)

So if you have read any of my other post you will know my sister in law is currently not speaking to me. Honestly I thought this was over the pizza incident but a recent conversation my other sister in law The one who still speaks to me makes us all think this fight started two years ago.

Ok story time we have to go back to when my son was maybe 14 months old. He’s now almost 30 months old. My boyfriend called me and said “my sister is outside she’s taking the baby somewhere can you bring him down”

I said “no he just fell asleep, why didn’t anybody give me a heads up. I hate when your family does this I’m not waking him up he’s not going”

My boyfriends sister had done this before, she’ll show up at the most random times no phone call no heads up nothing and just be like “I’m taking the baby.” And I genuinely appreciated that she wanted to spend time with him. But again a lot of times then I had to wake him up early or have her stand there and watch me as I tried to feed him quickly before he left or he’d be in the bath. And I really just don’t see why no body could have called or sent a text “gonna be there in 5 minutes.” Like how does no one in his family know how to give a heads up.

Anyways do y’all think I was wrong for putting my foot down and not letting her take him? What would you guys have done? Really any advice would be nice because I’m just amazed this is still even a thing.

Thanks in advance