Her egg at it’s starting weight should be 2.7 so it’s actually losing a little under. I wouldn’t touch the humidity and just let it keep going. Weight loss will fluctuate and usually lose the most weight in the middle of incubation, or at least mine did.
Are you sure? I took the starting weight of 693 and multiplied by .15 to get that it should lose 103.95 grams over incubation. Divided by 50 days, that's 2.07 grams a day.