Do we know - in this story - what Jenny knows about the moment of happiness. Until Enyos shows up to explain - and Enyos only showed up because the elders knew Angel was getting less unhappy - Jenny knew that him being happy was strongly discouraged but didn't know specifically why. She may or may not necessarily know that HAPPY=Loses Soul.

So Jenny wouldn't have a clue what Buffy is playing at, Buffy doesn't have a clue what Jenny's playing at, and I think neither of them really know what they - themselves - are playing at.

It's a big old ball of confusion.