Hi. Your pretty lady looks gravid to me. Have you got a lay bin in her enclosure yet? If not, now is the time. They prefer to have at least 10-12” wide and long and to save them from a lot of digging, about 5-6” deep of moistened play sand (or a 50/50 mix of sand and soil). While she may not just yet be ready, it’s best for the bin to stay there and when she needs it, she’ll have it. I also like to add at least a couple of stable ways in/out. Do read my blog that was linked above for more info.
Regarding her temperament, it sounds like she is just a ‘normal’ sassy veiled girl. Veileds are very often somewhat friendly when they are young, but once they mature the sass and spice comes out, especially with the girls. It is important to continue to work on building and maintaining trust with her, even though she may never stop trying hissing or trying to bite. In time, she’ll have you well trained and accepting of her sass.

The only other thing I have to say atm, is to offer a wider variety of feeders. Wax worms are great little fatty treats and crickets are a good staple. Try adding some roaches (dubia or discoid), silkworms, bsfl or grasshoppers.