Emeline this is Ana, Ahoatu's daughter. This is what I know from my dad....his father Penisimani was adopted by the Latuselu family but his real last name is "TAUFA". I don't know why he was adopted or if there was any relation to the Latuselu family. The name "Young" was the shipping man that he worked for and that's how he got that name.
Hope that helps.