She’s arm paddling
One of the best things you can do is to have her take a lesson. Then her abs can be sore instead of her arms!
The $50 paddle I mentioned above is a Cannon Cascade. I bought it for a spare but have used it several times with my little SOT just to see what it’s like. I prefer my other paddle ($250+) but the Cascade’ll do the job. The important thing is that it’s made in so many lengths that one of them is bound to be perfect for her. Most paddles come in 220 to 240 cm, a few down to 215 cm…not much choice for us small paddlers.
Lesson…
Taking a lesson is a great idea, but if she isn’t game for that, do a little online research on Greg Barton’s forward stroke clinic. You can probably find enough info to get her started. Also, depending on the width of your boat, she might want to try a shorter paddle. Going shorter will keep the paddle closer to her where most of her power is. Even if she only uses a little torso rotation with a shorter paddle, she will minimize her effort and maximize her effectiveness.
Carlise X-stream
THis probably won’t help, but Carlise used to make an interesting paddle named the X-stream. The shaft was aluminum, but the paddle as a whole weighed about 15 oz less than my Seclude. It was also about $20 cheaper. The interseting part was that you could remove the paddle blades and put on a different stlye. It never caugt on and Carlise no longer makes the paddle. Maybe you can find one floating around your local shop or on ebay. Good luck,
-MEAT
The Seaquel
> Was she using your Seaquel or your $20 older, heavier paddle?
She was using the Seaquel. And I’ll have you know that my other paddle cost well over $22, made with the finest wrought iron. 
Build yerself One…
is always an option. We use spruce shaft/ply blades paddles that can be built for about $20. I allow good afternoon or evening’s work to make one. If Enchant (or anyone else) wants it, I can e-mail a set of instructions & some pix of ours - n/c, of course.
Rick