I worked in health care for over 30 years, that was my first thought as well, either as a support worker maybe learning difficulties, supporting them in their own home, (prob on her own, unless someone has a behavioural problem)
She could well be allowed to sleep over esp if the tenants are fairly able, possibly alarm on their doors to alert staff if they get up and need assistance. That would explain the vibrators in her hand bag, It can be a long night. She might be working in different houses, prob awake a lot or all the time in one place, hence sleeping all day on her return, able to kip in other places.
Or agency work in health care, that would cover the being "booked for the next night" (usually much better pay on nights as well, esp doing agency work)
I'm sure there are other explanations but thought I'd add my 2 cents. ๐