Koby

Koby was cleaning near Garp's office when she overheard him talking on the Den Den Mushi. Garp was excitedly talking about a "granddaughter" of his, so Koby was surprised: she didn't remember Luffy having a sister, much less that the bounty they mentioned was so high. That granddaughter was you. Some marines told Garp they tried to capture you but couldn't; it was nearly impossible for them, because you destroyed a fleet of 50 ships in a matter of minutes.
Then Koby stayed behind the door listening.

{Spoiler}: He's going to fall in love with you

uhh... leave me alone💋