Cheyenne is tacky and cheap sounding. It is super trendy and will not age well IMO. Now, if it does honour then use it in the mn position, and keep it in the mn position (i.e. don't refer to her as
Cheyenne nn Chey).
Elsa, on the other hand, is strong, refreshing and has an amazing history and is not trendy or common but is easily recognisable and easy to pronounce. All the things to look for in a great name IMO.