At risk of stating the obvious (Tahra and other fanatical klicky-poppers will certainly know this, but I have never seen it mentioned anywhere), there are two types of that torso which PlaymoDB describes as ‘female curvy’. Here they are:
One has ‘sloping’ sides and the other has more obvious ‘hips’.
The ‘hips’ version was introduced in 1987/8, but the earliest example I can find of the ‘sloping sides’ torso is in sets 3965, 3967and 3968 released in 2000 and special 4588 released in February 2001. Both torso styles are still in use today.
Just thought I'd mention it!