Hers was the hardest for me even though she was an old lady of thirteen , because it was an accident , and I feel I could have , should have , saved her , if I had only checked on her earlier . Somehow her hind legs had slipped off the back deck , under the chicken wire fencing . Her hips were weak , and she could n't pull herself up . And that 's how I found her , just hanging there .
According to the above context, answer the following question.
Why was she an old lady of 13 ?


She was a pet and pets die at about 13 years old .