Brand was born in Buckinghamshire, England, in 1979, and enjoyed making people laugh with her impressions as a young child.

[3] In 2008, she collaborated with Katherine Parkinson, one of her friends from university,[9] on a BBC Radio 4 series called Mouth Trap.

[12] Also in 2010, she made a guest appearance on the song "Stop Giving Me Verses" by The Hoosiers, which was an attempt to break the world record for the longest single ever released.

[13] In 2011, Brand took part in the BBC Learning project "Off By Heart Shakespeare", where she played the role of Titania from A Midsummer Night's Dream and delivered a performance of the speech "Out of this wood do not desire to go".

[3] Her debut play, 3Women, starring Anita Dobson opened at Trafalgar Studios 2 in May 2018 and is published by Samuel French.

[22] As of February 2021[update], the comedy feature film Good Luck to You, Leo Grande, scripted by Brand, starring Emma Thompson and directed by Sophie Hyde, is in the pre-production stage.