Default appearance:

p4margaret, yellow eyes, blonde hair, wavy hair, headband, lipstick, makeup,

Default outfit:

p4margaret_velvet, dress, long dress, pencil dress, blue dress, long sleeves, pantyhose, black pantyhose,

You can also add her book with:

book, grimoire

https://civitai.com/models/1143725/margaret-persona-4-illustrious