Love Lauryn... very cute!
Sometimes you do just have to let go of a theme and I think it's better to forget going with a theme than it is to name your child you only kind of like in order to stick with a theme.
Dh's initials are JET and they run in his family, so we planned to always use those initials if we had sons... by boy #2, I realized that was NOT going to be easy and there were just other names I really prefered, plus, I considered the idea that we may indeed have a boy #3 and then what in the world would we do??? So we broke the trend.
However, all that being said, I think you should push for Caroline.. it's a beautiful name & it fits your theme.