From what I understand Tyshiria (and this is probably from
www.inherownwords.com ), Sara Fleetwood and Stevie were real good friends (presumably before the Stevie-Mick affair!). One night they stayed up writing this song. A song of 18 verses or something. If the much-mentioned motive for the writing of 'Sara' is to be believed, then the idea of this girls' slumber party/support session, and the heavily emotional reflection/statementof the song, all seem to make sense, to me.