Angie, David's advice and experience are some of the best here and I'm glad they were helpful to you. I second his story of post-TX weakness. I was flat on my back nauseated 24 hours a day for 3 months, and didn't even begin trying solid food for a couple more.
But it does definitely get better. I noticed a big jump at about 8-9 months, although there were small victories of course prior to that.
As my internist told me when I saw him around that period, commenting on the 30 pounds I'd lost and everything else, "You've literally been starving, so don't expect instant recovery." Ain't it the truth!
Of course we're all different, our metabolisms, our reaction to treatments. So there are no hard and fast rules. Take it easy, treat yourself very carefully and life will soon improve!
All the Best to you and your sister.