She will get over playing with it. She's only little. I agree with FF, no harm seeing the surgeon and see what he says. They're all different.
In a former life I used to work in theatre at the Kids Hossy usually in general doing lots of hernias. Most parents choose to get it done for cosmetic reasons. We generally did them over 18months but that was a long time ago.
My DD has one. It's gotten less noticeable as she's grown. She's 5. I never planned to do anything with it unless it caused her pain. It hasn't so I haven't. Can't see the sense in a GA for what is generally covered by clothes anyway.