What do you suggest if my child had umbilical hernia repair with mesh. now she is having unexplained swelling of lips and face.?

Unknown: Unexlained swelling of lips and face suggests an allergic reaction, and should be seen right away by your pediatrician or an emergency room. Whether or not it has anything to do with the hernia repair would depend on when it was done. There are no known true allergies to synthetic mesh products, as they do not invoke an immune response. They can have problems though, so call the surgeon as well.