Former sixties model and actress, poor Chrissie is the younger sister of Jean Shrimpton and was Mick Jagger's girlfriend from 1963-1966. You can guess from the songs she inspired what their relationship was like: Under My Thumb (inspired after Mick finally managed to 'tame' the pushy Chrissie), Stupid Girl, 19th Nervous Breakdown, Play With Fire, and Back Street Girl.
(photos of Mick and Chrissie from the super amazing blog (Diet) Coke and Sympathy Chrissie modeling photos from Youthquakers)