Lyric discussion by kevinyc 

Cover art for You Don't Have To Cry lyrics by Crosby, Stills, Nash & Young

While both Crosby and Nash went out with Joni Mitchell, Stills went out with Judy Collins (aka the Judy in Suite Judy Blue Eyes). Given that this song is about a very busy performing artist and given that they were going out/breaking up at the time this record was made, the song is probably about her.