I don’t think ‘invasive’ alone works, although you could try something like ‘invasive of caregivers’ personal space,’ ‘frequently violates personal / physical boundaries,’ etc.
I also like Raudona’s suggestions from #2:
>>umformulieren: "doesn't respect (any) boundaries", "forces physical contact on her" o.ä.
I am only a layperson and not an expert, but in general contexts at least, I would really underline the advice to use a complete descriptive phrase rather than trying to rely on any single word.
In fact, it seems to me that concrete examples could really help, both in understanding the behaviors and in preparing other caregivers, teachers, aides, medical staff, etc. to deal with such a child.
Grabbing a woman’s breasts or lifting her shirt to touch her skin (#1) might or might not have a sexual component in the child’s brain, I don’t know. (I would wonder if that child had previously been breastfed, for example.) A child ramming his head up under a woman’s chin (#2) also reminds me somehow of a young animal, like a calf or a goat, butting its mother in search of milk — but it’s even more obviously dangerous, as it could break a tooth or even a jaw.
Either way, from the woman’s perspective, those actions are certainly beyond what she should have to put up with. So from a practical or even legal perspective, the institution might need to provide a second adult as backup: a strong helper available to physically subdue or restrain the child in order for the woman to do her work and still feel safe.
Sorry, probably anyone who works in the field of autism is aware of things like that — but I’ll leave my brainstorming anyway, just in case it helps to see a sample discussion in English.