What can my mom and I do to boost our energy during such a stressful time?

My mom and I are visiting her sister whom we are very, very close with. She has been given just a short time to live after finding out that her cancer has spread to her brain, liver and lungs. We are optimistic that with agressive treatments, her die hard will to get better and her reliance on natural rememdies will help carry her through longer and give her more time on earth with us. Each day we get up ready to tackle whatever tasks or adventures my aunt is physically up for but find we are often ready for a nap by 10 am!! We can't seem to kick this lethargic feeling. Any suggestions on what mom and I can do to boost our energy levels???