Juliet is the daughter of Val May, the theatre director, and his first wife, Penelope (formerly Rish).
May oversaw all eight episodes of Heil Honey I'm Home! in 1990, a sitcom featuring Adolf Hitler and Eva Braun for British Satellite Broadcasting in 1990; only the pilot was ever transmitted. In 1995, she was nominated for a BAFTA award for Rory Bremner, Who Else?, and won a BAFTA Children's Award in 1999 for Microsoap produced by Andy Rowley, with whom May has collaborated on a number of productions.
She directed all twelve episodes of Steven Moffat's 1997 school-based sitcom Chalk. She then directed Robert Bathurst in My Dad's the Prime Minister, and Dawn French and Catherine Tate in Wild West. She also directed some episodes of series V of Red Dwarf. She found it hard to work with the science fiction elements of the series and left before the series had completed. The remaining episodes were directed by Rob Grant and Doug Naylor.
- The Treasure Seekers (1996)
- After the Chalk Dust Settled, featurette on Chalk Series 1 DVD, ReplayDVD.co.uk, prod. & dir. Craig Robins
- "Series V Production". www.reddwarf.co.uk. Retrieved 2008-01-07.
- Grant and Naylor Look Back, Red Dwarf Smegazine, issue 11, January 1993, Fleetway Editions Ltd, issn 0965-5603