Devon Wilson , (born: 1940s, Milwaukee, Wisconsin- died: February 1971) was a “supergroupie” in the 1960s- she was romantically linked to: Jimi Hendrix, Mick Jagger, Brian Jones (Rolling Stones), Eric Clapton, Duane Allman, and many others.
Devon ran away from home her hometown of Milwaukee and had lived on the streets of Las Vegas by the time she was 15 years old.  She allegedly became a prostitute at the age of fifteen while living on the streets (which might explain the line ‘been riding broomsticks since she was fifteen’ in the song Dolly Dagger, Hendrix’s song to/about Devon Wilson.) 
“Eventually settling in New York, Devon became a regular at places like the Scene and the Fillmore East. She met Jimi Hendrix in 1965, and they began an on-again, off-again relationship.”1

Wilson was a regular presence in the studio when Jimi was recording when she became Jimi’s personal assistant. 

“Devon’s hard-partying lifestyle eventually took its toll as she became addicted to cocaine and heroin. Jimi became increasingly disillusioned with their relationship and toward the end of his life, he had been distancing himself from Devon and was spending more time with other women. Devon Wilson was the subject of a Hendrix song, Dolly Dagger. According to engineer Eddie Kramer, Wilson was in the control room as Hendrix recorded the lead vocals. As an aside, Hendrix says "Watch out Devon, give me a little bit of that heaven."  She died a mysterious death in February 1971, when she fell from the Chelsea Hotel in New York.”1
 

1. http://www.groupiecentral.com/