Changes in appetite in 96 yr old with rectal cancer. What does it mean?

My 96 yr old mom has been in hospice for about 8 months. She has a large rectal tumor. While her appetite has generally been good, although she's had significant weight loss over past few years, now she's about 68 lbs or so, for the past few weeks she's started to eat less. She's said that the aides at her small residential care home are not giving her enough to eat, but then she tells me what she's getting and it sounds like enough to me. She also seems to have lost interest in foods she used to like. She has pretty bad teeth so I'm also wondering if her ability to chew is just about gone. She also has a Foley catheter and she no doubt has chronic UTIs. Today she was more weak than I've ever seen her. I've spoken to the aides and the house owner and they're trying to address the issue and give her what she wants, but it seems she's always got some complaint about the food. Not sure if this is the beginning of the end.