I think 87 is little high. 82-85 is good. But as long as stiletto is not regurging then it should be okay.

You can try:
Boiling the pinky then offering it in a small deli cup(when it's cooled off)
Washing the pinky in ivory dish soap, and rinsing it off then offering it. Again in a deli cup.
Everything you try should be in a deli cup or small container. Try braining again but with a deli cup.

I'd try to feed once a week. If she doesn't eat, then wait a week then assist feed, then try something new the next week, ect. Do that as long as she is keeping down the assist-fed mice. If she is really active then it might be too hot or she might not have a good heat gradient. You should add more hides and fake plants. They don't have to be anything special.

I hope she'll eat for you!