AITAH for telling my mom that my daughter can go with her to see my grandmother and great grandmother if she can be back at 6pm? (6 hours from when she originally asked)

A bit of a backstory, my mom and husband have always butted heads. They’re both very dominant people, and both love to make decisions as the head of the household. We’ve had quite a few spats with my mom, so this isn’t new.

Today, my mother text me around 11am asking if my eldest child could go see my grandmother and great grandmother. My great grandmother is sick, so we’re trying to get as much time with her as possible. I spoke with my husband to confirm he was also okay with it, and he said yes if she could be back at 6pm so that when he gets home from work, (he leaves before they’re awake and gets home 2 hours before bedtime. He doesn’t get much time during the week with them) he can see her and spend time with her before her 8pm bedtime. I thought that was a fair compromise, given that there were now 5 hours before then, and my mother lives 5 minutes away, and my grandmother lives 15 minutes away. My mother, however, didn’t find this deal sufficient, and absolutely lost it. She has been texting me consistently, long books about how I’m allowing my husband to control me with our kids. (Mind you my mother is a single mother, and has been my entire life, so she’s never had to consult with anyone about her kids) She told me to “keep making it harder on her if I want to”, and she’s tired of asking to take my kid(s) with her and us saying no for no reason other than to say no. And she said “I’m allowed to get (daughter) and have visitations with her without a 6pm curfew for bed and dinner time!”

Am I the asshole? My mom sure is doing a great job of making me feel like it?