Hürrem sent letters to Sigismund II, King of Poland and Grand Duke of Lithuania, the contents of which were mirrored in letters written by Mihrimah, and sent by the same courier, who also carried letters from the sultan and her husband Rüstem Pasha the Grand Vizier. After Hürrem's death, Mihrimah also became Süleyman's advisor and confidant, urging him to undertake the conquest of Malta in 1565, and sending him news and forwarding letters for him when he was absent from the capital. She enlisted the help of the Grand Vizier Semiz Ali Pasha, and promised to outfit four hundred ships at her own expense. However, Süleyman and his son Selim prevented the campaign from proceeding so that the admiral, Piyale Pasha, could stay in Istanbul with his new wife, Gevherhan Sultan, Selim's daughter. It is also likely that she encouraged Süleyman's decision to launch a campaign against Hungary in 1566, where he met his death at Szigetvár.
