87 is a little warm IMO. I'd try to cool it down to 80-82 if possible.

Besides feeding, how often do you try and handle her? If its only for feeding she may be slowly associating you picking her up with being fed and it puts her immediately in strike mode when you pick her up. And after feeding they can sometimes be defensive, so that's not that unsurprising.

If she's aggressive all the time, then my advice is to just bite the bullet and reach in and grab her and pick her up. If you need to, don a pair of gloves. Then just continue to hold her in your hands until she calms down. Corns can be pretty active, so it may be a while. Only when she has calmed down do you put her back into her cage. Then give her a day or two off, and repeat. If you keep doing this she should eventually calm down.

99% of corns are puppy dog tame, they can be flighty sometimes, especially when they're young, but most grow out of that quickly and calm down a lot. However that 1% can be little spawns of Satan that never get out of it. You may have ended up with that 1%. Try my advice above. At the very least, she should calm down enough that you can handle her safely w/o being nervous or worry about getting bit, even if she still tail rattles and occasionally strikes.