lol Perona is making little baby ghost with Mihawk, don't worry for her
Carrot has a dynamic, with the crew and Luffy. Yamato doesn't have that dynamic. Luffy doesn't care much about her yet and she has no dynamic with the crew. She indeed has a good personnality, a moral pillar and what look like a dream, but she still lack the most important thing, a post, something that would make her needed on the Sunny, something she is good at.
And that.. is nowhere to be seen right now.