Well if that's the case maybe Aqua had a closer friendship with Ven then she did with Terra and somehow Ven
trusted Sora to become the next keyblade master. Seeing how Terra already chose and
maybe Aqua didn't have someone to choose so chose the person Ven would've. If we follow Lenexa's theory, instead of Ven's connection choosing Sora, it was Aqua's. When Roxas was formed, he took the form of the strongest memory of Aqua's which
might be Ven like how Namine was formed. She was formed by Sora's sterongest memories which is of Kairi.
Does that make sense?? I'm not sure if Aqua liking Ven is true. I'm not into BBS. So far I'm only in Days. Akuroku is more important than some friendship thing to me.