My daughters have given plenty of tax or bookkeeping assistance to friends (up through Schedule C, and with QuickBooks) as well.
Fiona (my older girl) tells a story of getting the W-2 from her burger-flipping job in Harvard Square (Bartley's Burger Cottage, for those who know) some years ago. She said, "Thanks! I've been waiting for this," and the kid next to her said, "What is it?" She started telling him what a W-2 was, what one needed to do with it, how to fill out a 1040, etc. and within seconds had *all* the kids who worked there gathered around her, hanging on her every word and asking questions (all of which she was able to answer correctly). She said that as she was talking, she was thinking to herself, "I sound just like Mom...."