Are you saying that there are elevated liver enzymes in her blood or her liver?
if it's in her blood, it's a sign of liver dysfunction... commonly as a result of damage incurred through excessive alcohol or drug misuse... does your mom drink? use drugs (including prescribed medications)?
elevated enzymes within the liver, such as elevated monoamine oxidases or cytochrome p450s, can be the result of the same as above, but that is usually an adaptive response to tackle frequent episodes of toxicosis from xenobiotics, which could be again drugs or alcohol...
the latter is reversible if the toxic onslaught is removed or reduced, unfortunately when the liver is damaged such that enzymes that belong in the liver are detected in the circulation, the damage isn't usually reversible and the liver repairs itself by fibrosis, which leaves scar tissue in the place of healthy liver tissue... doesn't mean she's in a lot of trouble though, provided whatever is causing the problem, be it alcohol or drugs or other, is discontinued.
her doc may suggest some B complex vitamins for her to take in the short term, which have to be taken parenterally, which means she'll have to self inject them for a limited time... make sure she does, as it will really help.