My mom might lose her hand due to negligence?

This is a long story, but the short of it is just seeing if this might be pertinent to malpractice or negligence and what the next steps might be.

My mom is in California and she's been in a nursing home for about 2 years. Her health has been on a decline due to diabetes and her kidneys failing. She does dialysis 3x a week alone. In the past month she's been admitted to the hospital and intubated 2x. During the first intubation she needed a certain medication. (I'm waiting to hear back from the nurses to see what medication it was. They are being ridiculously difficult to get ahold of to even find out any updates on my mom in general.) My mom can't have BP or an IV in her left arm as she has a fistula for her dialysis there. The other one had an IV. Apparently this medication is only meant to be given through a PICC line and instead they attempted to give it to her through a regular IV in her hand.

This severely inflamed her hand to the point where it has caused necrosis and a massive wound on the back side of her hand. When I was out there they didn't tell me any of this despite me being kin and my mom not being able to vocalize her wishes, comfort, care, etc.

Now they are stating she may lose her hand or a large part of it and they keep apologizing about it.

There are more things I've despised about this hospital but this is the most pressing issue I have aside from them telling me she was almost ready to be discharged and then having to hear from a different sibling they contacted that she isn't as verbal as they'd like and needed permission to cut her hair for an EEG. But her losing her hand due to them giving her medicine incorrectly seems just so wrong and horrible.