How can I reduce or lift these jowls and slim my lower cheeks/jawline?

Getting local tum. lipo and Acutite/Facetite will really make a big improvement in the shape of the face and tighten up the skin  nicely and quickly with only 1 day downtime.

FaceTite can internally tighten the skin in the lower face and neck. After all the skin has been heated and contracted, we shape the neck with liposuction to give definition and remove stubborn pockets of fat. In one quick treatment, we can tighten skin, remove fat, and contour the lower face, jawline, and jowls with only a weekend of downtime. Keep in mind that combination approaches will give you a more significant improvement as opposed to a single procedure. I recommend getting a consultation with a board-certified cosmetic dermatologist and facial sculpting expert. Best, Dr. Emer

A small amount of Kybella could be used off-label to reduce the jowl fat. Alternatively, you could consider a nonsurgical and energy based skin tightening procedure. 

Thank you for the question Emily. 
It is hard to give a comprehensive reply to your question since only a portion of your face is visible, and I am missing the details of your age and other information. 
In my practice what I have found to work well, for women who have high cheekbones and fullness in the mid face, as you say you do, and who are in their late 30s and up, are thread lifts using threads of different compositions. 
They lift the sagging skin and reposition the tissues during the procedure itself. Over time, as the threads are dissolved under the skin, they stimulate your own collagen production, providing subtle lift to the area of concern. Depending on the type of threads use, results last from 12-18 months or longer. Average cost is around $3000 and up, depending on the number of threads used. 
Alternatively, if the sagging around the mouth is from lack of volume around the ears, filler to this area may help redefine the lower face better. I typically use 2mls of filler or more for those, again dependent on the individual face, and cost is around $1300.