Sorry, Austin. Didn't see this one.
It appears to be in focus, so that's an excellent start. The blown highlights in the background are a distraction. Seems that a different angle would have eliminated them. The biggest issue with this one is the one you've pointed out--she looks dull and you need to either reflect some light onto her or use fill flash. Assuming you have an assistant, my first choice would have been a reflector, probably silver.
I don't understand why on-camera fill flash (not from the built-in flash. yuk!) caused so many problems. Fill flash is not a full blast from the flash. It's a much smaller burst. Did you have the flash on a manual setting or use it's automated fill flash setting (not necessarily preferred)? Experiment with your flash in your hours of boredom

and figure out what settings work best in what backlit conditions.
I like the way you've framed her with the rocks and your DOF choice, though I might have blurred the background just a bit more. All of that action is better defined than I care for.
I'm not a big fan of the 3/4 pose you chose for this subject. She doesn't really have the body or the attire to make that pose flattering. You might be happier with a head-to-chest pose. Less body in the shot would also put more emphasis on her face.
If I'm doing people photos to show clothing or an attractive body I, obviously, include as much of the body as possible. If I'm doing a portrait because I want the viewer to connect with the person, I generally want the face to dominate the frame. A chest-to-head shot would be very flattering for this one, particularly with that beautiful hair.
Do some posing research. There are many ways to pose "larger" women such that you de-emphasize their size and bring out their attractive features. She has very nice face and hair. Use those features to make an attractive portrait. Posing and photographing women is a very challenging aspect of the hobby. Study what the pros do and practice. Your subjects will appreciate the extra effort to bring out their good features and hide the rest. It's a rare woman that doesn't have good features that will make a beautiful photograph. It's also a relatively rare photographer who can consistently deliver good female photographs, regardless of the subject. That's why the pros get paid the big dollars.
Men, in general, don't give a rat's behind and basically just want the photo session to end. However, the same principles of posing generally apply to men, though the lighting is much different. Head to the library. There are many photography books that can help you with this type of portraiture.
Another small item: When hands are on hips, keep the fingers together. It's much more attractive.
Gary