When one reads (or writes) historical fiction, some modern preconceptions must be suspended.
Sometimes these things are small.
Example: Egyptians often walked around half-dressed. Or entirely naked. (Have you ever been to Egypt in August? It's really flipping hot!)
Sometimes these things are big.
Example: Egyptian royal families were incestuous.
Yes, incest was common in Egypt's royal family, a handy way of keeping the crown in the family. (However, the rest of the population tended to shy away from marrying their brothers, sisters, fathers, etc. Go figure.)
Incest tends to make modern readers squirm. I still think it's gross, but now I just take it with a grain of salt. In fact, National Geographic reported earlier this year that King Tut was the son of a full fledged brother-sister marriage. That goes a long way to explaining his club foot and the cane he needed to walk, probable results of a genetic bone disorder.
So was there incest in Hatshepsut's time? Yeppers. There's just not much I can do about it. I suppose I could re-write history, but that just seems wrong. (Although I do like the idea of having such power. Mwahahaha!)
Has there ever been a topic in a book you've read that made you squirm? Did you keep reading? Is there a topic you've shied away from as a writer?