Kellie,
Tell her not to worry about working with the tube, it's amazing how we can make it all work out. I coached all my teams with the tube, I just tucked it into the waistband of my pants. Some people taped it to their stomachs, which is another great idea. I would do a can before leaving for work and take a break at the half way point and either go sit in the car or in the bathroom to add some more into the tube. I used a syringe to feed, I didn't hang a bag or anything like that. I would put the tip of the syringe in the tube and fill the tube with food, letting it go in however fast I wanted it to. Lift and lower the syringe to slow or speed it up. I spent days at Busch Gardens while I was still dependent on the tube. I have always used a back pack instead of a pocket book so a few cans of food fit just fine. I also always kept some in my car for emergencies. It's sort of like packing an adult diaper bag, you have to think ahead!
Your sister can return to work with a tube, it just takes some simple planning.
Minnie