I agree with the suggestion of taking over the medication or giving your Mom a designated area to store and take her meds.
This is also the rule in my house, with our four legged family members so close to the ground it has to be that way (for us).
Good Luck, I hope you work this out so that Mom and the Yorkies can live together without your being afraid.
__________________ Cheryl,Mom to  SophieKate |