Okay so see I think I feel the same about Caroline/Carolyn, they really seem like two different names and I know 3 Carolines and they are all pronounced like majority of you said with the -line ending. I don't like Madelyn, it doesn't look right... and I hadn't thought about this before but I know of 2 Madeline's and they do actually pronounce their names with the -lyn ending....
hmmm I'll have to do some more research like PP suggested and see.
I also like that Madeline was my Great-Grandmother's name... I just don't know if it was her fn or mn or how it was pronounced, although I believe it was with the -lyn ending too.