As a lupus pt., I sympathize with your sister and your family. It is so kind of you to want to help her.
I agree with everything VeeJ said and thought I'd give you a few helpful hints I've learned along the way. I have SLE and I don't know where it will attack next.
A hot tub bath is great for inflamed tissues.
Paraffin wax bath really helps hands, feet, elbows, anything you can fit.
Hand/wrist/thumb splints provide support and protection from hitting hands on hard objects
I'm very sensitive to light and sun, so I apply a high SPF every morning and carry some in my car. I turn off flourescent lights at work and use lamps, etc. I sometimes wear dark glasses indoors if needed.
I have to drive a lot, so I wear gloves to keep the sun off my hands and had my windows darkened. I recently found a head covering that is SPF 50 that has saved me so much pain! I highly recommend SPF clothing if she has to be outside or in the sun.
I love soft heating pads, but have to use them for short amounts of time.
One of the hardest things to deal with is the fatigue. Due to the arthritis, I also had to quit jogging. I learned to plan my energy throughout the week. If I overdo on a good day, I'll probably spend the next in bed. So, I conserve by stopping activity before I'm exhausted. Also, keeping a regular wake/sleep schedule has helped immensely. This takes a lot of discipline.
Ready-made meals are helpful for supper after a long day at work.
Dry skin is another problem, so moisturizers are important.
Exercise is important, so yoga, pilates, and tai chi are recommended.
An electric toothbrush makes that task easier and there are floss systems that are easier to use than the regular stuff.
A lot depends on her symptoms, I've just included what has worked for me over the years.
I wish you all luck. Reading up is extremely helpful, so go for it!
Please post again to let us know how she is.