There are a lot of questions you might want to ask a woman with 5 kids.
But this isn’t one of them. That’s weird. Kids aren’t assets and don’t “do” anything for you regardless of whose they are.
A better question would be, “what level of control would I have over how your children are raised in our house.”
You have to go into a relationship with a single mother knowing that inherently those children will be a burden. Either you’re okay with that or you’re not. No need for stupid questions like this.