Above are two different versions of Baby Princess Sparkle, that came with the Princess Baby Buggy playset.  You can see they are identical, except for the purple glitter color in their symbols.  The one of the left matches the dark purple found on Glory, Windy, and Twilight.  The one on the right matches the fuchsia of Gusty and Moondancer.  Is one variation "rarer" than the other?  I honestly can't say, since Baby Princess Sparkle is pretty rare already!