I can't wait for pictures... I would say if there is some yellowing she might be a young adult. Your vet should be able to give a pretty accurate guess.
She seems in a bit of rough shape, take lots of pictures... you'll be amazed by the transformation. I think it took a little over a year for Punky to fully 'recover' from the hard life on the streets. Little things keep getting better and better with her, I still notice small improvements even to this day.