They all refer to girls names in song titles, all being top 20 hits between 1955 and 1985
1. Take tea before US state keeping unmarried waiting (9)
2.Third month estimated time of arrival (8)
3. Teenage Mutant Ninjas brought her into the limelight (7)
4.A girl lost for fourpennyworth of Morton? (6)
5. Dolphin pair wake her up to go home because it's late (6,5)
Colin- the problem with my strawberry patch one is that the 1974 version by the artist that the clue points to fell well short of the Top 20. Maybe there was an earlier version by someone else that also fits the clue