Elizabeth,
There are several things that I quite like about this painting. Your use of edges in particular are wonderful and give the composition a sense of energy and movement. I think that you have undertaken a difficult work due to the use of less-than-best reference photos. I think that I would have been far too intimidated to undertake this project.
The thing that bothers me somewhat in the portrait is the distortion in the face of the teenaged girl. The cheek/jaw area on the right (the girl's left) looks like she just returned from the dentist with her lower cheek packed with cotton. Try holding the painting up to the mirror and the discrepancy will probably jump out at you.
I think it's coming along nicely, however. You always seem to figure it out in the end. Just keep plugging away -- that's the encouragement I keep having to give myself.