Black widows and funnel webs are not tarantulas.
About the only tarantula species you would really have to worry about venom-wise are African and Asian (Ornamentals and Baboons especially). Though, there still have been no fatalities associated with their venoms, they have been known to be excrutiatingly painful. You may not die, but you may -wish- you were dead for a few days.
Most North American and South American ones are not considered to be especially dangerous. Doesn't mean you can't potentially have an allergic reaction to the venom still. When dealing with anything venomous, allergy is really something that many people take far too lightly, imo.
One thing I would be concerned with is the urticating hairs. Some species are much worse than others, and children being children - having the habit of touching things and then sticking their fingers in their mouth or rubbing their eyes, definitely something to keep in mind. Some species are much worse than others. Having a child damaging his/her eyesight because of a pet tarantula's stinging hairs would not be a good thing.
Pick a few species that appeal to you and then do your research is all I can recommend. Hopefully one will fit your needs/interests.