So far there has not been much mention of Leia in the prequels,
however, this is bound to change when Episode III comes out.

Princess Leia was born 18 years before ANH. She was born
during turmoil, as the Old Republic was crumbling and the Empire
was gaining more and more power. Her mother was Padme Amidala,
the wife of Anakin Skywalker, who had fallen to the Dark Side and left,
becoming Darth Vader. Little Leia did know know of her true heritage,
and was brought up by the kindly Alderaan nobleman, Bail Organa.
When she was very young, Leia proved to be no ordinary princess.
She refused to be presented at court, and instead wished to become
a Senator. When Bail Organa became involved with the Rebel Alliance,
Leia backed it wholeheartedly, regularly performing dangerous missions.

When Leia was growing up she had a best friend named Winter
that was often mistaken for the Princess since she
was more regal while Leia was more rough and tumble.

To Submit Your Information on Prequel Leia
ladyofminastirith@yahoo.com
May the Force be With You