Summer is 4 pounds, and is very fragile and small also. I let her out around 8 every night and she doesn't go out again until 7 am, sometimes later on the weekends. She also goes out every 6 hours during the day. I think some bladders are stronger than others. I would check her out if she isn't going a good amount though. Just wanted to let you know it isn't real unusual that she went that long.
She is 2 years and 6 mths. old.