Left our child for a booty call and now wants to babysit our newborn?

We’ve been foster parents for five years and had 11 kids in our home. Out of those, my MIL has only met about three. Once, we asked her to babysit so we could go on a short date night. We were gone 90 minutes, but 45 minutes in, she left to meet someone from a dating app. She said it was fine because our 18-year-old foster child was home — but we asked her to watch our 10-year-old, not leave it to another foster child who shouldn’t have that responsibility. We also stopped letting her watch our dogs after they kept coming home sick from things she fed them, despite repeated warnings about their food allergies. She’s talked negatively about me multiple times. It doesn’t hurt my feelings, but it makes me question her intentions. My husband always defends me, but it’s still hard to hear. I have also never said anything negative about her because I know it would hurt my husband to hear something rude. I always ensure that I speak respectfully about her, even when voicing my concerns. Now I’m almost five months pregnant, and she hasn’t reached out to me directly — only through my husband. She says she wants to babysit the baby. I told my husband I’d consider it only if it’s in our home, where I work from home and can keep an eye on things. Still, I’m uncomfortable. I know my husband trusts her more with our child than our foster kids, but to me, a child is a child and all deserve the same care. My MIL is who she is — selfish, and not likely to change. My husband’s an only child and still helps her constantly, which I respect. But I don’t know how to move forward. Should I let this go and give her another chance? Or just limit things — like once a week, no more?