Is ghusl obligatory upon the wife if her husband has intercourse with her without penetration, and he ejaculates but she does not?

Ghusl is not obligatory upon you if your husband caresses you without penetration, unless you experience ejaculation, even if your husband ejaculates. Ghusl becomes obligatory for two reasons: penetration without ejaculation, or the emission of semen due to a wet dream, caressing, or other causes.