Originally Posted by Paul the Kayaker
I'd say if your plan is to swim her to make her more comfortable in the water she may not be your girlfriend for long...
On a more realistic note, get her a drysuit, a better higher float PFD, and a really good helmet. Make her feel safe and warm and keep her at the top of the water when she swims.
^^^^^This, for starters - the drysuit, good PFD and helmet, warm booties, gloves, be ready to suit her up until it's hot out. The next thing would be scale back your ambitions of having her challenged from the word go. Get out on some mellower water. Remember that she may not be as gung ho as you and may be doing the whole thing out of her love for you, rather than for excitement and thrills. If she loves you enough to do stuff that scares the hell out her, maybe you should be ready to spend time with her on mellow desert floats and places where the scenery is more of an attraction than the whitewater.
If you really want her to swim a rapid, the Little D wave train on Westwater is a good swim in July or August when the water's warm and the flow's down.