'they added one more child than I was told at lease signing... Now another one coming... I wouldn't have chosen them if I knew all this. Be careful as this is discrimination in regards to family status. You should inform yourself of the FHA rules on discrimination against families. This could become a very costly position if you, with very high penalties and fines. They have not paid rent in full, just issue the 'pay or quit' notice as per your state law requirements. If they don't pay, be prepared to move forward with an eviction.
I'm wondering where these children are popping out of? Perhaps this is the posters main concern. When people fill out the application they usually know what children they have. My application has who will be living in the home or something like that. As a landlord, I'd be concern is she taking in foster kids, running a day care or did she intentially not fill out the application truthfully. These are all things that a landlord should be aware of.