Have you seen her actually do the peeing in the inappropriate spots? If not, she may becoming incontinent at that age, which would cause her to lose urine anywhere she sits or lays, at times.
Thank you for your responses! We're on Day 6 and I think her behavior may be very slowly improving. The Purina HA's 1st ingredient is Rice Flour, which I think causes her skin to be itchy (new issue not seen on her Purina L.I. grain-free food), so I'm thinking of making a very slow transition...
My Ragdoll is only 3 years old and is 'crunching her body' (see pic) and periodically lip smacking as if her stomach is uncomfortable or she's nauseas. She does this multiple times a day, but doesn't vomit. My vet feels she has food intolerance and would like her to be on hydrolyzed protein...