Saddle on my BMX bike is super low too. So is the saddle on my DJ. And the saddle on my hardtail, while not slammed, is still too low to be a good pedaling platform. But ask me how often I sit down on those bikes. Doubt you were sitting and spinning on a BMX bike. I'm referring more to people who are riding their road bike/hybrid/XC bike on totally non-technical trails having their saddle too low.

Aw, now you guys have me all off topic! I was trying to be all helpful in the beginning, and now I'm ranting about saddles.

Anyway, now that I know how tall you are, this is the size you want most likely, a small or extra-small (14-15"). That bike ('08 C'dale F7 Feminine) is stupid overpriced though, Bikepedia says it was $380 new and they want $450 for it. And even though the bike in that picture is a women's specific, don't limit yourself to women's bikes. A unisex bike may end up feeling better. You should have come here last year, geez. I would have had a decent bike with a bunch of upgrades to sell you.