"Is there any way to distance myself from her during this time without being a jerk to her? I, as of this moment, never want to have sex with her EVER again, but I don't know if I can resist when she decides She wants it. "

A. Tell her if she wants sex, that's all it'll be. You're still leaving. That sort of thing happens all the time with divorcing couples.

and/or B. Have sex with someone else. Gets you less attached to your STBX.