Really? So Yoda talks about another hope for the Jedi which then leads them to Bespin where Vader reveals his parentage to Luke who then calls Leia through the force and it didn't make you think that holy ****! They are related? Huh. Well I guess everyone is entitled to take what they will from the films.
To me is wasn't about family, it was about another person who was force sensitive. That's about it. It's easy in retrospect now to look at it and say it was obvious, but the comment was vague on first viewing. Hell, I know there is some theory that who Yoda was referring to was not actually Leia but rather Vader.