With the variability of morphs increasing evermore as different combos and lines are brought together it's a tough call to make...lavender and diffusion alone make for a pretty wide range of darker and lighter snakes, and with a females generally tend to be darker...add hypo and it just makes it more difficult to judge what is...is...
We can speculate, cast expert and novice opinions alike but jmho til you breed it out and prove it to be or not to be you are kind of stuck, unless they offer to take her back and refund your money. As of right now you can't disprove she isn't hypo, opinions and best educated guesses aside...Fwiw she looks like, best guess, a beautiful plasma. Like Susan said she has great diffusion. Good luck with her, Jessica