) I don't think that Caroline sees a triangle. (And at this point there isn't one.)
The reason I asked about Carolines interference with Lizzy is because of what we were told in chapter 10:
"Miss Bingley saw, or suspected enough to be jealous ... her desire of getting rid of Elizabeth."
If Lizzy was interested in Wickham as Caroline indicates when she refers to him as Miss Elizas favourite, then she would have been better off leaving things alone and let the events take its course. But instead she does talk to Lizzy defending Mr Darcy from whatever Wickham could accuse him of. This does not seem to be in Carolines own interest, at least not to me.