Complex sentence: It is assumed that Hatnofer died when her son had already achieved his high state position under Hatshepsut; hence, the rich funerary goods must have been provided for by her influential son, Senenmut.
Split into simpler sentences: It is assumed that Hatnofer died when her son had already achieved his high state position under Hatshepsut. Hence, the rich funerary goods were certainly provided for by her son, Senenmut.