Formal:
* Elle porte des boucles d'oreilles. (This is the most direct and literal translation.)
Informal:
* Elle a des boucles d'oreilles. (This is a more colloquial way to say it, meaning she has earrings on.)
* Elle porte des créoles. (This specifically indicates she is wearing hoop earrings.)
More descriptive:
* Elle a des boucles d'oreilles pendantes. (She is wearing dangling earrings.)
* Elle porte des boucles d'oreilles en or. (She is wearing gold earrings.)
You can also use the verb "mettre" (to put on) for a more active sentence:
* Elle met des boucles d'oreilles. (She is putting on earrings.)
The best way to say it depends on the context of your sentence.