While it's common for multiples, I wouldn't be surprised if it was just one especially if this was her first pregnancy. I generally have more singles with first time moms. A lot also depends on her overall health and genetics too. I have one doe that is part ND that has more singles that twins. However, her last kidding she had twins. You are right about ND having quads sometimes. Had my first set of quads this year from a ND cross doe! Hopefully there's another kid hiding in there somewhere, but don't be disappointed with a single. Her next pregnancy is likely to produce multiples.