Actually, all said and done, I've given her the responsability of bringing songs she wants to do into the band. Success? Nil. Out of about 100 that we perform, she has learned all the words to about five. My rule is, and we all know it, "If you want us to learn it, YOU learn it first."
Girlchild is 18 yrs old, but very immature. Lovely voice, but very untrained. She has much trouble hearing and feeeling what is right as far as intonation goes. When suggestions are made, she pouts. I have talked to her, one-on-one, and she usually cries and pulls together for the next performance, then she's back to her old tricks.
I have learned that she possesses none of the joy in music that is necessary to carry a performance. She's in it for the attention. Sadly enought, when I asked her to join, she had us all fooled.
Maybe, hesperis, your suggestion is worth another shot, then let Mum handle it!
Thanks again for so many useful hints.