Maria,
10 lbs. in 4 days does sound like a lot. Today, my mom complained of not swallowing properly. She too is losing her appetite...but, we offer milkshakes,icecream,hamburgers....anything at all that would sound appetizing. She's maintaining her weight so far. Hopefully, your mom had a bad few days ...and will start gaining weight soon. I do notice some days are harder to get my mom to eat than others.
Good Luck. Keep in Touch.
Mel