Maryellen is a Girl Scout. In 1954, things looked differently within the Girl Scout organization.
Girls wore berets and badges were sewn onto the sleeves of their dress.
Girl Scout calendars were produced every year.
It's unclear whether Maryellen will eventually have a GS uniform added to her collection. I have re-created my own outfit to show as example of what GS uniforms may have looked like in 1954.
Other interesting tidbits about Maryellen, her BFF is a boy named Davy. She and her siblings have bunk beds. She enjoys roller skating. She is a cartoonist. She speaks Italian. She becomes a TV-news feature.