"Nice one Steve, but you could improve it by doing these 5 little tweaks:-
1. Soften and merge that garland shadow to the contours of her head and hair.
2. Add some modeling to give some roundness to her hair in the 'shadow' areas at the back to sit her against the background in 3-D
3. Round off that shoulder a tadge (Unless she's a bony chick;-)
4. Hair casts shadows too!, ease a little soft shadow onto the dress.
5. Same with the necklace, a little hint of a cast shadow on the skin would help.
I'm sure she's going to love the finished result. Merry Christmas to you both.
Wiz
OH! Nearly forgot. Use the Quick Mask > Radial Gradient > to add a little darkness around the edges of the portrait so that your eye is drawn into that beautiful face