You should have used some white reflector or fill-in flash to get a little more light into her beautiful eyes.
I agree. This is the biggest thing that stands out to me. Having your subject lower their head is an open invitation for bags under the eyes if you don't have enough fill light...the umbrella probably isn't helping either. Here we have a young lady, and poor lighting has aged her into her 30's.
There are some other things. I'm being picky here, but the old saying goes: if we know better, we do better. There are some unspoken "rules" to good portraiture and posing, especially when it comes to ladies:
1. Never show the back of a woman's hands. They appear to be flat and manly. Try to pose a female's hands so that you're photographing the side of the hand, which is the thinnest part.
2. Sleeveless = bad. It's rarely flattering, especially for women. She's pressing her arms tight against her body, which is making the undesirable effect even worse.
I like the umbrella. It adds a splash of color, which is important here considering the black dress and drab background. You should have rotated it so that "Dunlop" was out of the frame however. Now instead of it being a cute accessory, it's become just a golf umbrella.
