Emma Geller-Green is the only child of Rachel and the second child for Ross. She is the half sister of Ross' son, Ben, from his first marriage with Carol. She is also the first niece of Monica's. Emma was conceived when Ross and Rachel had a drunk night; on Joey's couch to be exact, while they were doing Monica and Chandler's wedding invitations. The whole thing was video taped by Ross unknowingly. She is named after Monica's favorite childhood name that she gladly gave to Rachel to use for her daughter, since Ross and Rachel couldn't decide on a name. Emma doesn't appear much, but is often mentioned.