Hi! This is a tough one but I just thought of something. Since mommy cat is still lactating, maybe you could contact your humane society or a local cat rescue group. With so many babies being abandoned, maybe she could be a surrogate mother to baby kittens that still need to nurse. That way not only will mommy cat be safe, she'll be helping some newborns get the nutrition they need so badly. Plus it might help her if she thinks they're her own babies.