My female jack russel just had 7 puppies last night,can the frontline flea control that we treat her with harm the pupies in any way?

Check the directions on the package. If it doesn't say anything about pregnant or nursing mothers, call the vet. This is one of the many details a responsible dog owner would have checked on long ago. For other things you not have thought about, see Woodhaven Labradors Articles (http://www.woodhavenlabs.com/articles.html#breeding)