Your mother can have a normal life span with
heart valve leaking. It depends on whether there is progression of regurgitation,
valve integrity, underlying cause, etc. An operation would be appropriate if your mother has severe shortness of breath with very little activity (i.e.walking up a stairway), etc.
I have known about my mitral valve regurgitation (moderate to severe) for the past 5 years and there doesnt appear to be any progression.