Why do you keep going on about looking after the grandchildren when mum is at work?
I’m not talking about mum being at work. Most children are in nursery, or some kind of paid childcare, and then go on to school.
The OP said that she doesn’t want to provide any childcare.
So her contact with her grandchildren is going to be solely at the mercy of their parent’s schedules, and supervised.
The fact is that most people are far too busy working full time, raising children, running a household, with various other commitments, which doesn’t leave much time for visiting relatives regularly. Certainly not regularly enough to be building any kind of meaningful relationship between them and their child.
No, grandma doesn’t need to make 100% effort, but you understand that she needs to make some kind of effort to build a relationship, right? Like “It’s a nice day, I was thinking of taking Grace to the park for a couple of hours”. Or “Yes, of course Ethan can come here whilst you attend your hospital appointment this afternoon. And you know what, I haven’t seen him in a bit, he can eat dinner with me and I’ll give him a bath. Collect him about 7pm?”
It’s hardly raising your grandchildren, is it.