Diagnosed With Heart Failure. Feels Tired And Has Breathing Problem. Suggestion?

hi my mother has just been diagnosed with heart failure, she is nearly 80, and was just wondering how long have we still got with her, she seems very tired and has breathing problems at night when she lies down, so now she sleeps with a pillow behind her back upright, she said she cant do much like she used to, even daily chores she cant do now, will she ever be able to get back to these? she has always been active as she could, but even standing at the bench imakes her tired,