Like what we know yamato current dream is to open wano kuni just like oden
Role on ship/identity is important for us to know her next dream. Because all SHs has the identity that make them have their dream
Identity/crew position - dream
Luffy - captain of pirate group - pirate king
Zoro - swordman - WSS
Nami - navigator - draw world map
Usopp - someone who always lies about how great he is + coward - brave warrior of the sea
Sanji - cook - find all blue so he can cook 4 seas fish in the same place
Chopper - doctor - find the cure that cure any disease (cmiiw a bit forget about it)
Robin - archeologist/historian - find the history of void century
Franky - shipwright - make sure his dream ship arrive at the last island
Brook - musician who has promise to his old friend - meet laboon to deliver their former crew last sing
Jinbe - fishmen - by joining future PK will rise the dignity of fishmen race/to show that fishmen can be a friend with human?
Yamato - ? - ?
Daughter of WSC - new WSC (nope)
Dragon? - reveal sonething about dragon (unlikely but there's possibility if the unread poneglyph give hint)
Apprentice? - ?
Log keeper? - ?
Kozuki retainer? - find the truth about kozuki connection with the world (seems likely but personally
i'd like the real kozuki is the one who will find truth about it)
Any other suggestion about yamato identity and dream?
But of course the first obstacle for yamato to join is her current dream. Will wano be open by the end of arc/by the time SHs leaving wano?
Will she leave momo who is the one that may guide the world to the dawn?
Will she discover something that make her think about a new dream/goal?
Then will luffy ask/accept her on his ship?