Basically, we want the kids 50/50 but she refuses as then she wouldn't be 'able to get as much money from us'- her words.
As stated, I am happy to pay for their upbringing. My bio father paid nothing towards mine, and I refuse to let me stepkids go without. But 50/50 is fair. Especially as their mother earns more than their father.
She just refuses to buy stuff for them- we actually had to buy new winter clothes for her house for them as she refused.