Kate Major -- of filing restraining orders against Michael Lohan fame -- has voluntarily checked herself into rehab ... TMZ has learned.
We're told Kate will get treatment for alcohol abuse. Sources close to Kate tell us ... she checked into a treatment center in Boca Raton, FL and will stay there for 90 days.
According to our sources, Major made the decision after her alleged drunken plane fight a few weeks back.
We're told Kate feels drinking changes her into somebody she isn't ... which probably explains how she started dating Michael Lohan in the first place.