My moms battling liver cancer for over a year & it has spread to her lungs. she told me it was at stage 4 & wanted to know how much longer she has.

Help her: She needs emotional and spiritual help , you and your family members along with friends make her end part of her journey in this world, as comfortable as possible, who can give time only he can give , but based unavailable data not much

Not exactly sure.: Stage IV liver cancer is, unfortunately, incurable. However, sometimes treatments can prolong a patient's life significantly. It is hard to answer your question without seeing your mom's scans. But, typically, life expectancy is measured in months to a few years.

Unpredictable, but..: It may be days or perhaps as long as a year, maybe even more if it's a grade i hepatocelular carcinoma. I am very glad you are there for your mother. Perhaps you can enrich her life so that she will say at the end, "you added a rich amount of good life to the time i had left.".