Nmom only wants to see my kids if they do something for her

I’m not 100% sure my mom is a narc but she’s definitely narc-adjacent. 7 years ago we moved away form where my mom and sister live. And since then we have traveled to them for every single holiday and birthday. My dad got really sick in 2020- it was brutal and fast and in that time we just stayed there which was fine. We needed to be together so that time I don’t begrudge her at all. But even after his death we trudged 3 hours to her for everything. She’s only come here if there was like a play or race or something to see. She went my oldest daughter’s entire sophomore year without seeing her run - meanwhile she didn’t miss a single race of my sisters three kids and even volunteered at them. Now it’s been a year. I’ve stepped back a lot and gone LC with her because I couldn’t take being taken for granted anymore. I don’t allow my kids to stay with her anymore bc she screamed at my adhd/anxiety diagnosed daughter that she couldn’t call me and said she was a burden on her dad and I because she caused us so much stress. Then she got drunk and cried to my 14 year old about missing my dad and essentially used her as a therapist. She uses my niece and nephews as designated drivers and I set a hard boundary that was inappropriate if she couldn’t not drink for one night then maybe there was an issue. My niece is a super nervous drive her and my mom made her drive scary mountain roads she was unfamiliar with at night at 16.

Long backstory sorry. But as of today she hasn’t not come to see her grandchildren in a year. She called me today and asked to see the girls for one day (“needed them for a day or two”) over their spring break and before I could ask what they were going to do she said “I need my storage unit cleaned out and I figure it will only take them a day”

Am I overreacting? I feel like they’re only valuable to her when she needs them but when I tell they don’t want to and it’s ridiculous to ask to spend their doing break cleaning for her (they’re 15 and 17!) I will get told I’m selfish, or I’ll get guilt tripped bc she needs help! I’m angry that I thought things were better lately but then she calls and does this…. But then she’ll make it a sob story for herself. She always does. First of all… am I wrong in thinking this isn’t a good request from her? Like selfish? Secondly… will it ever not hurt when they do this?