You have my sincerest sympathy. I lost my cat last year after 21 years together, and he was incontinent towards the end. It’s very hard to say goodby to a dear friend.
Please don’t second guess yourself after she’s gone. There is rarely an obvious time to let your pet go, and it’s all too easy to wonder afterwards if you made the best choice. Remember that you made the best decision you could during a very difficult time.