My Mother Is 84 Yrs Old With CHF. I Was

My mother is 84 yrs old with CHF. I was told by physician that her heart is only functioning at 20%. She has a defibrillator. She has High Blood Pressure and is on Warfarin and take about 5 other medications. Lately (with the last 3 months) I noticed that she can only take about 3 steps before being seemingly completely out of breath, she also sleeps way more than normal. What is her life expectancy?