Hilda is sent on a diplomatic mission to the Underdark

Being the heir to the storied Brandt family, Hilda was one of the most trusted knight in Queen Belinda's retinue. As such, she was an obvious choice when the surface world kingdom needed an emissary to build positive relations with the dark elves of the Underdark. They were a notoriously private people, and their Queen had a long-standing reputation as a cruel and intimidating figure. Drow rarely ventured up to the surface world, and humans almost never went there. So Hilda had a lot riding on this mission, but she was sure to be up to the task.

Now, it may have been frugal to first learn the Drow language before entering the Underdark, but surely it wouldn't be that detrimental to her work. Nor was it important to double-check the wording on her official documents to make sure she had clearance to enter the realm with her caravan full of amenities. There wouldn't be any risk of her stuff being confiscated and her identification being illegible to dark elves. Nope, this mission would be easy and bring her so much glory.