Hello Richard,
It is a very nice painting. What my feeling is, is that you have a tendency to give several volumes in the face, the same kind of 'roundness'. Would like to see the source-photo for comparison, maybe I can go more into detail about this. (Or maybe the source-photo shows it exactly like you painted it. Then it's my mistake

)
Something is bothering me about the little flower you placed right under her face. The light accent it makes distracts the attention from the face a bit too much.
And I really like the way she holds her open hand, it gives the pose really something energetic in a subtle way.
Greetings,
Peter