No. If a size two is something important to you (as opposed to a general “good appearance”) than you should/would have made it a point to ask the references. If you were to meet someone for (say) a business reason would you hear in advance something that may affect the business deal? Probably not. (and no, I’m not equating shidduchim with a business deal even though thats what many people think of it as) If you had an outstanding feature that was the first thing people notice when looking at you, would you want a shadchan telling someone in advance?
More than the fact that you would have said no had you heard her size, (not gonna harp on that) but the way you say you had already decided there wouldn’t be a second date before she was down the steps seems much worse. Saying no in advance is one thing. But buddy, once you saw her and were out on a date with her, and still didnt give her a chance, thats just plain not fair.