With a commitment to proper care, ferrets make very good pets -- for anyone, including families. They do require exercise, training, attention (they like lots of attention!) and regular veterinary care, including vaccinations. In addition, homes must be thoroughly ferret-proofed. Ferrets are wonderful animals, but they are not low maintenance, inexpensive pets.
However, ferrets are banned in some jurisdictions. The argument against ferrets often includes concerns over injuries from bites -- arguments that aren't very well-founded. Due to concern over ferrets causing injury, especially to children, various agencies have come out with position statements on ferrets as pets. For example, a Canadian Veterinary Medical Association Position Statement on Ferrets as Pets once stated "it must be concluded that ferrets and infants should not be left together unattended" (though this appears to be an old position; the statement no longer appears in the listed position statement on the CVMA website). The American Veterinary Medical Association also no longer seems to have an official position statement on ferrets as pets, but the organization once stated "It is also recommended that no ferret be left unattended with any individual incapable of removing himself or herself from the ferret." Statements such as these unfairly give the impression that ferrets are dangerous, and one has to wonder why ferrets have been singled out for such dire warnings, when other family pets have caused also caused serious injuries to children. While these statements have merit, the warnings could be applied to any kind of pet!
Having said that, ferrets do have sharp teeth, and must be taught not to nip (just as one must train a puppy not to bite while playing). However, even a well trained ferret may try to nip if he or she feels cornered or threatened. Given that young children and ferrets can both be excitable and prone to rough play, interaction between ferrets and young children must always be closely supervised -- for the protection of both the children and the ferrets. For older children who are able to be calm and gentle, a ferret can be a fine pet. It really comes down to a personal choice - know your child and make an informed decision whether any pet will fit into your household dynamics. And always remember that whatever the situation, interactions between children and any pets must be supervised.
More on Ferrets: Ferret Facts and Care Guide