Yes its fine.
Personally, I would let her meet dogs as well (not strays) as long as you think they are vaccinated (downtown Toronto, I doubt there is any problem) plus run on the grass, meet as many people as possible, everything, just stay close, make sure no dog attacks her and that she stays away from feces etc.
IMHO, the gains from socializing her as early and as much as possible far outweigh the small chance of her catching a disease.
Personally, I would let her meet dogs as well (not strays) as long as you think they are vaccinated (downtown Toronto, I doubt there is any problem) plus run on the grass, meet as many people as possible, everything, just stay close, make sure no dog attacks her and that she stays away from feces etc.
IMHO, the gains from socializing her as early and as much as possible far outweigh the small chance of her catching a disease.