BUT i think you should definitly consider the color combo of orange and blue. Or blue and green. the combination look great together. Blu and orange are simply amazing together and if your cousin has a fairer complexion than it will look great on her. If she has a darker complexion I would tell her to go with a baiger color but lay off black. A paler pink or blue would look really nice as well. So thats my opinion.
BUT PLEASE TELL her to consider orange and blue because it would go on really any complexion and is a great combo.