I would think it might be better in a year or so when her immune system is stronger and she will heal faster. also unless she is already potty trained i would think there is a higher chance of infection while wearing a diaper.
See what her pediatrician says. My guess is, generally surgery when someone is a child is better than when an adult, but there might be mitigating factors (such as the chance of it coming apart naturally). Also, surgery being better done on a young person does not mean they have to be only 1 year old. Is this child in your care? If not, I would let her parents handle it. They can talk to her pediatrician, and maybe to a surgeon or specialist, before deciding what to do.