What is the ruling on cursing a woman who places her foot on the Mus'haf, when a post on Facebook calls for either cursing or ignoring it?

One should not intentionally look at or disseminate offensive images of the Qur'an. Insulting the Qur'an is an act of disbelief (kufr), and disbelievers are generally cursed. However, cursing a specific disbeliever before their death is a matter of scholarly disagreement.