is there a way to keep your MIL from your child on the dads days?

I do not trust my current MIL, she’s been on and off drugs since before my husband was born. she doesn’t respect my requests or boundaries (tried driving with my 6m old in the front seat going down her gravel road, feeds him things i don’t allow like artificial dyes and soda, and anything i ask, like not to kiss them on the mouth, she will do anyways) she’s never liked me whatsoever, she’s one of those weird boy mom that’s basically in love with her son.

anyways, i have been thinking about divorcing my husband (for multiple reasons, not to do w his mom) but I wouldn’t trust this women to babysit my dog, nonetheless my actual children! is there anyway i can keep her from babysitting when dad his the kids??