In my opinion, it is highly unlikely that you can cross-infect your children with HBV unless you have very poor medical or personal hygiene practice, because HBV is a blood-borne virus and generally requires blood-to-blood(wound) contact for infection. That said, however, anyone who works in a profession with possible exposure to blood and bodily fluid(police, firefighter, medical etc) should be vaccinated against HBV, beside practising the Universal Precaution (assume everyone and yourself are infected with something). Your children should also be vaccinated against HBV, not from you but others.