As said, a very nice work, and quite a bit of technical skill displayed.

-Overuse of I and of telling/not showing, as mentioned. Use the first person, but don't just use it to break the fourth wall! Specifically, the entire first section felt like a summary of an introduction. SHOW her history, her career, her attitude...have her follow the links on her parents' computer and surf, we'll learn all about her business and Katrina while getting worked up. Give some internal monologue about how she feels towards incest, rather than just telling us how she's wired.

-It was believable until the last scene with her mother, which felt very forced. A sudden, well-timed confession, unlinked to the father? The father unknowingly having the same tastes? The daughter not knowing her dad can't use a computer? It would help the first scene to describe what was written in the email...what was implied/explained/demanded...if she'd started off with something like, "I know you've watched me and fantasize about me, so meet me in the study at midnight, and come naked" it might strike a believable note...the reader would understand she'd just luckily stumbled on the truth, even with the wrong evidence. The mom's giggling confession of a ten-year secret over brunch is still hard to swallow, though.

-One or two minor spelling errors, just run a quick spell check.

-A couple delays in the plot. The conversation with her family, particularly, didn't accomplish all it should have. Characterize more -- what does she feel, what are her interests, hobbies, pet names, past experiences? If the plot is sexual tension -- which is what it seems, and fine -- then build it with everything you do. Take this from an awkward conversation -- which on re-read, has the mom wierdly inquisitive for knowing the answers already -- to a semi-public tease, with caresses or whispers or flashes or... something.

Anyhow, that probably seems like a lot, but really it's just the nudge towards really truly good, not any condemnation; this is a damn fine work, and I hope you'll share your efforts some more here at the Library. We don't pay money, but there's a lot to say about providing a forum to authors and access for an often-marginalized community.