Great news that she's doing so well.
On the subject of her going out - my cat was in indoor cat from the age of 5 and she was fine (in fact, when we got the dog I'll swear the cat used to laugh at the dog having to go outside in the cold for toilet!). My cat was a couple of months off 18 years old when she succumbed to renal failure, so staying indoors for the best part of 13 years did her no harm at all.