MIL clueless as a caregiver

Quick edit: I genuinely think she is oblivious, not that she doesn’t care. I also don’t leave her with him. My husband and I are in the house but just doing chores and things and are in and out of the room except for one time where we slept in the next room because we’d been up all night for multiple nights with him. I have only let her come over three times ever with our LO because of this: the last time was the worst and I haven’t had her back since. I don’t “keep letting her do this.”

I guess I’m just wondering if I should blatantly say hey you’re a terrible caregiver and it scares and enrages me how awful you’ve already been to our son even if you didn’t mean to be, or if I should drop it and just not let her come over anymore at all and only go off about it if she presses the issue again.

MIL born and raised in an impoverished country with poor sanitation, no clean water, no refrigerator, and none of the standards of safety or hygiene of the privileged state of America, but has been here in the US 4 decades and raised multiple children and helped raise and watch children not her own. She has been very pushy about wanting to come take care of LO. LO is 3 months old and we are first time parents. When she comes over she’s done the following: 1. Left him alone on a changing table like she was setting him there for a nap and left the room: no awareness at all that he could roll off and hurt himself. 2. Left him covered in puke and poop: found his onesie covered in dried-on poop all up his back and on his skin but with a fresh diaper on. Then proceeded to feed him and cook after holding him covered in poop (with poop all over the changing area that she left there). Barely rinsed her hands with water and calls that “washing her hands.” 3. Didn’t feed him for 6 hours straight (made him wait four hours past when he was screaming for food when we told her when to feed him and how much). And simply told us “he’s going to be hungry.” 4. Ignores his screaming and crying and just leaves him lying in the crib like this, then gets mad at me for invading her time with him when I go to pick him up. Does the same when she holds him and does nothing to soothe or comfort his screaming and crying and gets mad when I take him to calm him down. 5. Put a folded up blanket on top of him in his crib and told me I need to be better about covering him with blankets when I put him to sleep (zero awareness of SIDS or suffocation risk). 6. Gets angry when I told my husband I don’t want her to visit several times a week, especially with total lack of awareness about caring for babies despite having raised multiple herself.

It’s insane to me how the absolute basics of caring for a baby seem to escape her and she gets angry and defensive if we gently try to teach her or if I have the audacity to want to hold my own baby when she is present. She prefers her native language and is very childish and sensitive to criticism so we have to tiptoe around her feelings and he has to explain it to her further in her native language (also speaking English). This stresses my husband out because she doesn’t take it well and has no awareness about her having any faults as a caregiver or as a person.

Anyone else have any experience with a MIL like this? Do you just tell her no more caring for my baby or do you just put up with her childishness and defensiveness and keep trying to teach her?