It is uncanny how exactly your mom and my mom are similar. She is also 87, prior independent, confrontational...anyway, almost exact.
she went in Feb 04. Her current rehab facility is the worst in terms of actual rehab. They don't do anything. For example, they have been in the process of decanulating her for over two months. The doctor ordered it. The staff didnt get the order. blah, blah, blah.
They are still feeding her mush (I sneak her in carrot cake).I'm the one who's gotten her to lift up a fork and feed herself on occassion.
I'm the one who's gotten her to write a little.
The rehab facility does NADA.
It's just the worst.
Her symptoms after all this time are much like your mom's. She has her good days and bad days. However, she has been in longer than your mom and is still having the same symptoms.
She can write her name some days, She speaks some days (often it's like she's forgotton how to speak with volume), she feeds herself some days.
I asked the doctor, who sees her about once every two weeks (can you believe it?), what about cognitive therapy? He replies "Do what you're doing and let her watch alot of TV" Gee Thanks! MODERN MEDICINE WHAT A WONDER!
The only saving grace is the nursing attendants. They are wonderful.
I ask a nurse to pay more attention to her and, of course ,the reply is "I have 30 beds to take care of". I feel like telling her that in Chad there is one doctor for 10,000 starving children, but I keep it to myself.
Anyway, this was more a rant then an answer to your question. For that, I am sorry.