Personally i believe bonnie to be related to akainu in a way...
Maybe daughter or wife{her age changing powers} or handler {she may be a spy for him}
Daughter as in....the way akainu addressed her after taking her from blackbeard {he soundes like a worried dad in his own way tho - and her response was like a rebellious child} ...
Spy as in... What if bonnie is actually a spy for akainu to either topple WG or the pirates.{we dont know his actual goal} Cuz escaping from akainu doesn't look like a easy feat and also oda disnt show his reaction on her escape...maybe he actually let her go.
And also why did akainu come in person if shes not important enough.
Now we see her at the reverie... Which is the last place a recently escaped Pirate would show up at.. Probably on a mission
What are your thoughts...{sorry for the length}