I bet it is not up to height so you have nothing to lose by entering the workers as well as the flat class. The workers are the first class of the day, so at least you would get the tickle out of her toes before the other classes. You would need to sort out your entries fairly soon though, as the classes are very popular (for obvious reasons!)
I agree with workers think you'd do well at them. And as for a hunter bridle have a look at Pidge and see what you think for breaking the white face up?
The chestnut in my avatar has the same white face (although on the left hand side rather than the right) - nice wide noseband breaks it up well. Double check the height of the noseband to make sure you have it in the right place. Stand well back from all angles - too high makes their noses look long and too low just looks silly!
see a nice wide noseband looks stunning on a chestnut with a white face
and as said by someone else here at least we stand out in a crowd. not that I'm biased towards these ISH chestnuts mind
you know I think Hattie is stunning and she can jump and you can jump big (I'm so not jealous!) so you would do well in workers. The bridle was a sabre one and I think from memory you can choose the width of the noseband.