No because then she would be my sister, and for me its a genetic thing where your sister cannot be hot to you. Sure you can be objective and say "guys find my sister hot because they say that she's gorgeous", but you can never infer that you think this way. For instance my older sister, I am told is a knockout, but I look at her and say I love her, but gross and she is a stick in the mud. Now Dina would definitely be tough to not think of as hot, but the genetics would prevail. However imagine when her friends came over from the gym or "work" for their slumber parties, just like marsha and jan had on the brady bunch. Dear lord, you'd be the coolest guy around just for that. And who knows, maybe at 15, going through puberty and all its weirds implication, one of my sisters (Dina) friends would throw a pity-f my way.
And then when you turned 18 or 19 your sister and her friends would be around 26-29, and for sure you would be scoring with them (After all, with Dina and her Hot friends around constantly, I'm sure I would have hit the gym much earlier in life and cared more about my appearance earlier, as well as getting major poon advice from them from a much earlier age and last but not least use them as bait for girls your own age. If your seen with older chicks at that age, the girls your own age are thinking "STUD?").
Now of course this would put a strain in the relationship with your/my sister Dina, but what the hell's she gonna do? Disown u? Of course not because she knows that when she turns 31 she'll be using you to get at your friends (which I may add have been carefully handpicked and weeded out to remain your friends. Just like the way she maintains her current work stable. No offence).
This is all assumming that Dina's real (as opposed to fantasy) sister is not even in the picture. That would be too over the top.