Just added another to check the process for Princess Sparkles. Be certain that you have the email address first then password, then url for your blog site. All need to be correct, or it will not load.  It should be noted that you have to choose a figure without a hat over it. These are for "Classrooms" and they incur a fee.
Once you have made one, any extra Avatars will load with no dramas. It didn't seem to work to add two to one post however. Happy Avatar making! I just love the voices and they really add class to the Avatar. Always wanted to be a Princess in India. Such a beautiful and musical language!