I'd stick with your pilates and walking, but add the Callanetics hips and butt exercises to your pilates routine. I haven't found *anything* like those exercises -- they're very hard, but they really isolate the hip and butt muscles, as opposed to things like squats and such which can't help but involve the muscles in your thighs. They're also really easy on the joints. Be patient with the exercises, they take a little bit to master, but once you do, there's no going back! You'll see results in an incredibly short time. This is a link to the Hips and Behind video; your local library probably also has one of her books, and there are many other videos.

One other thing: for the cottage cheese syndrome, I've had good luck with dry brushing. Five minutes before every shower with a stiff natural-bristle brush, circular movements, always towards the heart, all over your body. Pay specific attention to your hips and thighs, of course. You may want to "work up" to dry brushing -- try brushing in the shower first, just to get your skin accustomed to it. The brushing gets rid of dead skin and stimulates circulation, so your skin will glow and the improved circulation really helps with the cottage cheese!

You might also want to try a firming lotion, since you should be applying lotion after the shower anyway. I think Jergens makes a decent one.

And drink TONS of water, of course!

Good luck!