Hulk9970
of reading
2633
Read books
If you want to go with someone younger then why not go with Yamato? I mean she’ll also be long loved being an Oni and it helps that she is strong and not as young as luffys generation to make it feel weird. But ultimately it’s all up to you so whoever you choose is fine, even though I still vote for Olivia. I mean you could just have robin leave the crew when she’s of age to go on her own adventure to find the poneglyphs. She would still meet luffy but just not be as jaded.
If you want someone to go with study what about Nico Olivia? She and especially Robin deserve so much better than what happens to them. She should be about the right age too with a wanderlust attitude that a pirate would need and robin couldn’t be safer than if she stayed with Whitebeard.