Helen Mary Boyd (born 8 November 1947 in Guildford, Surrey, England) was a 1960s London fashion model; she is the younger sister of Pattie Boyd, who married Beatle George Harrison.
She was given the nickname "Jenny" as an infant by sister Pattie, after her favorite doll. She dated folk-rock singer Donovan, who wrote the song "Jennifer Juniper" about her. Later she shared an apartment with Magic Alex of Apple Corps's Apple Electronics subdivision. She also worked at the Apple Boutique in London.
She married Fleetwood Mac drummer Mick Fleetwood on June 12, 1970 and they had two daughters: Amy Rose and Lucy. After divorcing Fleetwood (and remarrying and re-divorcing him), Jenny eventually married drummer Ian Wallace (formerly of King Crimson). She attended UCLA in the late 1980s and earned a Ph.D. in psychology, and became a clinical consultant and author. She co-authored a book about music and psychology, titled Musicians in Tune.
She traveled with the Beatles and sister Pattie Boyd on their famous trip to India in early 1968.