User blog comment:Monkey.D.Me/Whose baby is that?/@comment-3986064-20110522142408

It could be Shank's because she is close to his age close to max 5 years apart Also in the wiki on Makino's page is written: "Makino is a very kind person, and was a close friend of Shanks, his crew, and Luffy. Makino appears to be a very prominent figure in Foosha Village." On the cover is shown their life after the time-skip, so it would be normal that that child is her, she's at least 30, so it makes perfectly sense to have a child. But if it's not Shank's it's still someone that is or will be important in the manga