[matese]

Hummmm, that's gonna be a tricky one, how bout when you walk her just as she squats to pee stick a pee pad under her so the pee goes on the pad, then praise her like crazy saying pee pee on the pad and give her a treat (or what ever word you use for pee pee) same when she poops, just as she hunches over put a pad under her the poop will go on the pad, again praise like crazy saying poo poo on the pad and give her a treat. Take pee pads and treats with you every time you walk her. This may take a while. On your first rain day lay a pad down in a designated area and tell her pee pee, poo poo on the pad.
I am formally from NY, was a tenant with no back yard and a pack of 3 yorkies, in rain, hail, sleet or snow, them in their winter coats or raincoats, me in my boots and umbrella out we went for their walks. Just a heads up in case you cannot pad train this 7 yo. AND THANK YOU for rescuing.