We are roleplaying in 5e D&D. Typically, I agree with DM decisions. However, a question came up on a decision that I don't agree with and I'm wondering if maybe I'm just missing something.
Our party includes a Drow warlock that is disguising herself as a half-elf. No one in our party has been able to see through this disguise and we all still think she is a half-elf. We are all still level 1, so I'm assuming no magic items are involved. I also don't believe that she is capable of casting powerful enough disguises to fool all of us (I say this knowing someone will find a way and post it). We have just finished a week long forced march traveling 14-16 hours a day.
Is there anyway that a drow could disguise herself as a half-elf convincingly, and would any such methods hold up to a week long forced march so that none of the party members would notice anything was odd? (I don't believe that she is wearing a permanent mask, because that would raise suspicion)
My goal is not to discuss rules (I added what system we are using in case it did become relevant). I'm mostly just wanting plausible story answers.
EDIT: I think the main problem with my belief is I didn't consider the option of dark skin. I mentally picture elves as 'fair folk'. I sort of bunched half-elves into the same category. I don't remember her description saying she was dark skinned, but if so it's quite possible.
On the other hand if she is trying to pass herself off as a light skinned elf, that is more difficult. Makeup at best is water resistant and would start to run from the sweat of 14-16 hours of hiking daily. If she brushed her face, makeup would smear. Clothes brushing against makeup would rub it away. If anything like that occurred then her obsidian black skin would show up in stark contrast against her light skin.
I guess it basically comes down to if she is disguised as a light skinned half elf or dark skinned. I don't remember for sure either way (making me assume it was light because I feel I would have noticed/remembered if it was dark).