Shirley Henderson was born in Scotland in 1965 and from an early age showed a deep passion for drama. She moved to London at age 17 and went on to graduate from the Guildhall School of Music and drama. She landed several small television roles until moving to the silver screen in 1995's Rob Roy and in Trainspotting the following year.
After appearing in several theatre productions Henderson was offered the role of Jude in Bridget Jones's Diary and then what may be her most famous part - the blubbering ghost Moaning Myrtle in Harry Potter and the Chamber of Secrets. Henderson was by far the oldest actress to portray a Hogwarts student, seeing as she played Myrtle at age 37 in 2002 and once more in a sequel two years later!
Oddly enough, the character she plays in Bridget Jones also spends all her time crying in a bathroom.
(Sources: 1, 2)