My daughter had umbilical hernia repair with mesh. Now she is having unexplained swelling of lips and face. Could these be related?

Doubtful. It depends on when the hernia was repaired in relation to the start of symptoms. If the operation was yesterday, she could be having an allergic reaction to some medication. If it was months to years ago, there is certainly no relation, as the mesh does not cause allergic type reactions. May be best to see her primary care provider to help sort it out. Hope this helps!