You ARE doing something to help your Mom...you are leading by example!
People tend to take notice of what you have to say about health/nutrition/weight loss when they see the results/changes it has made in "your" life.
Another way you can help, is by doing exactly what your doing...cleaning out the work out room. Maybe going for a walk with your mom. Buy her some pre-packaged lean cuisine meals and add some extra veggies and lean meats to it. Bring it up to about 400-450 cals. Then say, "Mom, this is what your meals are supposed to look like portion wise". The truth is...she can have her KFC and still lose weight. Just go to the calorie counters thread, and look at the "Daily Intake Thread"...there you will SEE what some people are eating...and it's not all grilled chicken and lettuce..lol!
You see, she can have the foods she wants, but you'll better help her (and have more success seeing results), if you show her what a proper portion size looks like. Small changes...small changes...people can do..but don't ask too much!!! Once she sees the results of her making those "small" changes, she'll be SELF-MOTIVATED to make bigger changes. One step at a time...remember!
All the best.