I can only speak for the Mongols, but the answer there is certainly yes! Empress Dowagers (The wife of the dead Khan/Kha'an) ruled the empire during interregnums between the death of a khan and the conclusion of the kurultai electing the new Khan/Kha'an. The most prominent of these women was Toregene, wife of Ogedei, who ruled for six years between the death of Ogedei in 1240 and the ascension of Guyuk in 1246. I would highly reccomend Jack Weatherford's "The Secret History of the Mongol Queens." It has controversial moments, but at the very least you could raid the bibliography for more sources!