Silly girls?

tonight i was out with my friends and a girl i know who has had a problem with me for quite a while came and started on me she started shouting and everthing and pushed me but i didnt retaliate, should i wait till shes on her own then retaliate or just leave it? but if i leave it then she will get the staisfaction to do it again to me or on other people help what should i do??