Thanks, all! I love Rachel and Rebecca, too, since they are SO classic and even rare these days, but my two best girlfriends are Rachel and Rebecca, so it would be awkward to name potential DD with one of those. I also love Reuben/Reuven, so that's a good one to add to the list, and while Ronit is another good possibility, a college friend named his daughter Ronit and I hear too many people calling her "rah-nit" instead of "roh-neet." Of course I like Rina and Rayna, but again, we have two friends (though not as close) with those names. :)
We'll keep these in mind!