Another thing to think about, when you get the costume, is child safety hazards. Thinks like drawstrings round, or anything that has to be tied around the neck. Buttons that aren't thoroughly sewn on or zipper pulls that you child could put in their mouth.
Since your buying from a large company that mostly deals in children's items you shouldn't have to worry, Wallao is most certainly CPSIA compliant. If you were to commission a costume, or make one yourself, make sure you, and the person making it, understand where hazards can come from. The last thing you want is your toddler swallowing a button.
Renaissance costume (Fabric bought, ready to make)
For the little one:
Elsa (main dess, coronation dress, and frozen fever dress)
Anna (main dress, coronation dress, and frozen fever dress)
Matching doll dresses to go with it.
Carolina Renaissance Festival 2015