Her grip is impressive. I recently thought of getting her to hold on to a specific item while I'm helping her, but I haven't thought of the ideal thing yet. This is also difficult to do around the toilet. (And I often find that if she really needs to use the bathroom, she holds on tighter) I also find that going quickly is better as we both end up less frustrated. I also make a point to be extra polite, and that seems to help keep her from getting upset, but the grip. Did I mention it's impressive?! Appreciate any other suggestions.
Geaton777 gave the same suggestion I would.
I always gave my Husband something to hold on to.
Him holding onto a washcloth, towel or a cloth teething toy did a few things. It kept his nails from digging into his palm (even though I kept his nails short). Because his hands were clenched they would get sweaty so the cloth would absorb moisture. Him holding onto a cloth prevented him from trying to hold onto the bedding or his clothing when I was changing him or the bedding.
I placed a grab bar in front of the toilet to help my mom stand while I got her up and down, that might work. (because the shower was across from the toilet and there was no wall I used a swing arm superpole, it did double duty at shower time.)