Hi.... Please seek professional help.
This might be a simple case of you overthinking about this whole scenario or you suffering from a mental health condition (like, ocd).
You can discuss with your mother about this particular habit of her and tell her that you prefer things clean and not ok with her not washing hands.
Also, if this habit of her is actually at an extreme level, where she is actually unable to maintain basic hygiene. Than she also requires a professional assessment, as it may be a symptom of an underlying condition.
Next Steps
Consult a Psychologist and a Psychiatrist.
Health Tips
Mr. Gunjan Maithil
Senior Psychologist
Cell: Nine Six Seven One Three Zero Three One Three Four (whatsapp)
Website:https://gunjanmaithil.wixsite.com/therapy
App: http://wix.to/fECHB08?ref=cll