The "lemon" in my name is a reference to
1) the male comparison of women to automobiles - "something to take a ride in", and
2) the concept of purchasing a "lemon" car - a car which a man is supposed to be able to ride in it, and drive it where he wants to go, but IT doesn't cooperate.
A lemon child is one which is a dud, from a utilitarian perspective - a child which doesn't obey, that is considered worthless and disposable because it doesn't give the adults what they want. A lemon child is one which has a mind of her own and is not easily exploited for adult profit. Mother purchased a lemon, and called me so.
I suppose that's not much different than an adult man (or boy) thinking I leave a bitter taste in his mouth. Or rather, no taste at all because he doesn't get to drink my lemonade.