As long as your daughter is fine with it. As for your Mother and Husband, well i would say, doesn't it prove these exist in the body, and isn't it a good idea to kill them off with a dewormer. Their reaction doesn't make sense, do they want her to just carry on being a host to these critters, it sounds like they think the dewormer itself has caused the worms.
I expect they are just frightened by it all. We become a bit de-sensitized to it all after a while.