Well I have seen Albino Deer, Opossum, Coon, and a Snake over my years of hunting, But never a Fawn with spots on it in Dec. So I would have to say even though it may be possable, it darn sure is not common.
As far as the question goes, if the fawns were that small, I would have killed them both to keep them from winter kill.
And I dont shoot spotted fawns.