Financial abuse even after divorce

My current partner's former wife is an extremely toxic individual. Now that they are apart, she uses various tactics to continue her reign of terror.

One of those tactics is financial abuse. She lost the children's prior daycare due to failure to pick the children up, lying about having to work to use their services, and refusing to pay her bill. Because her childcare is partly supported by government assistance, she was unable to get new daycare services until the bill was paid off. She told my partner that he had to pay for the rest of the bill, totalling over $200 in order for their children to be accepted into a new daycare. She claimed this was his half of the bill, which we found out later was a lie. She never paid a cent of it. Even though my partner never used daycare while they were in his care, she still expected him to fork over the cash.

She agreed to pay for half of the divorce and then told him the cost of the divorce was double what it really was. She was the one who left the marital home and cheated on him but still tried to get spousal support from him.

Most recently, the children lost their daycare again. Fortunately, this daycare provider is willing to testify on my partner's behalf in court (her always sticking him with the bill, neglecting to get the children when she was supposed to, & how dad was the one who'd consistently have the children on her weeks).

My partner has paid most of the costs but refused to continue paying for her half of it since it's too much of a financial strain. He provides more than 50% of their care, pays her nearly $800 in child support monthly, yet is expected to pay for all of the extra child expenses.

He has two children with her. Their oldest will be going to school next year. She wants him to be the "residential" parent for school (making him responsible for both the children's care every week while she gets them a couple hours a few days a week and every other weekend), but is unwilling to change their shared parenting order. Why? Because all the children are to her are pay checks.

She recently got fired from her job but asked my partner to watch the kids so she could pick up an "extra shift" at work ... the real reason she wanted him to get them: one of them was sick and she didn't want to have to take care of a sick child!

The level of abuse, both financial and emotionally is exhausting.

We've been documenting everything with the intent of him gaining sole custody so the children have stability. At this point, I think we have enough solid evidence to win custody, if you want to consider this a winning matter. I really think she'll abandon them completely if she loses custody and the financial benefits which come with the custody. As unfortunate as that is, at least the children will have stability.