I honestly think as long as you're drawing
something (careless scribbles do not count), then you will improve. Even if for an entire week you're drawing nothing but eyes, it will help. When I first started drawing around grade 3, I sat down by my bedside and drew one thing every day. Granted, the quality wasn't exactly top grade, and the paper wasted could probably make David Suzuki cry, but I digress. If she is persistent and diligent in her practice, there will be progress. Obviously she won't be able to see it right away, even in a few months.
If she wants some help improving, here's a good website:
http://www.posemaniacs.com/
There you can do things like gesture drawing, negative space, etc. It helps a lot with anatomy and dynamic poses. Another suggestion I have, although not thoroughly proven, is to jump out of your comfort zone. Try something new and fresh like perspective, or animals, or landscape. So far I can see she's done sweets, girls and that strange mr.giggles. I'm sure that's not
all she's done in those 4 years, but some variety would be good.
Also, it would be helpful to pay close attention while drawing. If you make a line that suddenly improves the whole picture, take a moment to contemplate
what you did to make it better. Once you figure that out, mentally file it away for future reference. Same goes for the opposite. If you there's something about your drawing that puts you off, but you can't quite put your finger on it, figure it out. That way you'll know what to and not to do. It's helpful to do this with other people's work too. Take the time to observe pictures that catch your eye if you're ever browsing deviantart. Ask yourself: What is it about the picture that's so special? The lines? The colour? etc ...
Oh~ and as a last note: Try reading the book "Drawing on the Right Side of the Brain". Very good stuff.