Can't? Won't?

Daughter had piano lessons as a child.  Years of them.  I finally tired of the battle involved with trying to get her to practice, and we stopped them.  She's doing special music in a couple of weeks, and wanted to sing and play Morning Has Broken.  She told me she couldn't figure it out, so she brought home her music book today.  I was helping her name notes.  She could handle the treble clef pretty well, but was stuck on the bass clef.  So she named the notes in one measure.  In the next measure there were 3 notes-- 2 were the same as the previous measure, 1 had changed.  She couldn't figure out the notes she had just named in the previous measure.  I was exceedingly patient, and eventually she figured it out.  I find myself asking at times like that, though, if it is a matter that she can't figure them out, or won't.  She managed to play all the notes through once, but doesn't want to take the time to work on it and get it flowing smoothly.  At  this point I'm thinking she won't be doing special music any time soon.