Instead that first sentence in the caption is more of an exercise is throwing a bunch of prepositional phrases together to imply that Nadine is thinking a bit more like a girl, specifically a late teen.
Another element I wanted to through in there is how SAVAGE teenage girls can be. Of course, they can be best friends, but that doesn't mean that a friend can't swing right into that BIGGEST ENEMY EVER!! mode and its fun to watch how passively aggressive they can get. There is a bit of that in the envious tone that Dee strikes. Notice that Nadine doesn't dispute the assertion that she has better legs than Dee, and probably has sized her up as competition already, something that Dee seems to have already done.
The whole caption was built around an exchange of dialog I had in my head, that of the "You're not helping! with "I'm not TRYING to help!" I had sent it to myself in email to remember, but didn't use it until I found an appropriate picture. This one has the perfect pose and look on her face that screamed to be captioned. From there, I worked up the angle of doing a favor, but the person that asked is no longer around to resolve the situation. I thought the idea of being trapped and then being "helped" out by a female friend had some great possibilities for fun.
DISCUSSION QUESTIONS: If you are making a caption, do you usually have BIG PLANS and then fill in the details? Or do you have little things, and try to make a BIG PICTURE out of them? If you are a reader and not captioner .. do you prefer captions that are constructed like a story (ie beginning, plot, ending all tied in a bow) or more of a "slice of life / moment in time"?