I would aim for the higher protein/lower calorie deficit. You will probably lose some muscle if you are losing 2#/week, and that muscle will be hard to gain back. At the lower calorie deficit you may even be able to GAIN muscle, so even if you are not losing as much weight, your body composition will be more favorable. 90g protein sounds low to me, but it may be one of those YMMV sort of things. The usual guideline I've read is 1gr/#lbm, but since a ketogenic diet is protein sparing, you might be able to get away with less protein. Do you have a way to keep up with your body fat? You could see how the trend is and make sure you're not losing lbm.

Jen

P.S. 10-20# weights can be pretty serious for a woman!