I don't like Laurel, but I just wanted to say that I don't think she has a mustache. It looks to me like she has melasma, which is a fairly common hormonal skin issue where the skin makes excess pigment, and it usually affects the forehead, cheekbones, and/or the upper lip, and it's more common in women. Being in the sun makes it worse. I have some myself, and the only way to treat it is prescription bleaching cream, super strong sunblock, and staying out of the sun. Laurel seems like she spends a lot of time outdoors, so it may be getting worse.
OK, PSA over. :)