I am a 55 year old single working woman would I be safe living on 102 St between 2nd and 3rd Ave?

It's not terrible, but I would advise you go south. below 96th street is the way to go

Yes it is most definitely.. just don't wander off alone to dark quiet streets and avoid the housing projects at night.

Yes. During the day Harlem is packed, and theres a lot to do. Just stay inside past sunset, it can get sketchy.