Trillian

Tricia McMillian (Trillian to her friends) is a highly trained astrophysicist.

She is also a keeper of white mice.

With a degree in maths and another in astrophysics it was either that or back to the dole queue on Monday.
Trillian

Born on Earth, she met a guy at a fancy dress party who turned out to be from another planet. He eventually turned out to be her boyfriend, Zaphod Beeblebrox.

Trillian appears to have had several fates: being eaten by the ravenous Bugblatter beast of Traal, being married to the president of the Algolian chapter of the Galactic Rotary Club, accidentally having Arthur Dent's child and being blown up along with the Earth after all.

These improbable fates may be related to her time aboard the Heart of Gold, which she found it a breeze to pilot in comparison to driving round Hyde Park Corner on a moped.