I have never known anyone with such an extreme and obvious pattern where EVERYTHING that involves the children has to have some money saving/scrimping aspect and yet anything that's for her personally is top quality, no expense spared.
She doesn't turn a blind eye and purchasing an expensive meal out for herself, and yet the kids get hot dogs in a flask. The kids want swimming lessons? Nah. But she has no problems dropping cash on new things for the home.
The kids need new clothes? Let's see what we can get from charity shops or vinted. She wants new clothes? Drops £200 at river island without a second thought.
I've truly never known anything like it.
There is absolutely nothing wrong with money saving ideas to entertain the kids etc and I know kids grow out of stuff fast...that isn't the issue here. I know most people have to do it.
However, she clearly has enough money to treat herself. Maybe she doesn't have the money to do both, but I don't know any other parent, who if they couldn't afford to treat both themselves and their children, would choose themselves.