My husband if paying child support for his 2 kids, but the mom is not taking care of the kids properly. They smell every time he visits them, one of them is really skinny and the doctor said that his wight is really low. She has not done anything about that, and there has been some other things. If my husband fights for the kids custody and gets it, would she be the one to pay child support if she has a job?

Yes... child support can and does go both ways.

Yes, and has to pay in many places if not working ( some states have a min required support)

Support is based in various ways depending on where, Here in GA it will take into consideration income of both parties, and the number of days each will have the kids, then a payment is figured from those numbers ( simplified version)

There are exceptions but generally the non-custodial parent pays support to the custodial parent. How much varies dramatically by jurisdiction as well as the particular circumstances in a given situation.

Your husband should get an attorney immediately. He needs advice to get his children out of a neglectful situation, and all the other questions, fears or apprehensions he has can also be addressed including financial.

my husband if paying child support for his 2 kids, but the mom is not taking care of the kids properly. they smell everytime he visits them, one of them is really skinny and the doctor said that his wight is really low. she has not done anything about that, and there has been some other things. if my husband fights for the kids custody and gets it, would she be the one to pay child support if she has a job?

You say the children smell when "he visits them," not when the children come to him - does he have overnight and/or unsupervised visitation?

You mention that one of the children has a low weight - did the doctor say it's a cause for concern? Do you think the child is being neglected and/or abused? My son weighs only a few pounds more than his sister who is two years younger than him, and he's thinner than her as well - that doesn't mean he's unhealthy; he just has a low body weight.

You stated that there are "other things" - would you mind sharing what they are? I'd just like to be positive that you actually have a decent case for a custody change so that you don't waste your time and money and accomplish only getting the mother ticked off.