Dizzy, Weakness, Shaking Legs, No Pain Or Fainting. Stroke?

Mother said she was standing at the sink, suddenly felt funny maybe dizzy, and then both her legs became weak and shakey my legs were knocking and she lowered herself to the floor by holding on to the sink. Never lost consciousness , never any pain. Once on the ground, her legs stopped knocking . Within a few minutes was able to stand again. Very scared, but is ok. Only symptom is numbness in the bottom of her feet . Question is would this be more likely from a back/ spine/ disc injury or could this possibly be from the brain/stroke? I know not typical stroke symptoms, but she is on Pradaxa for afib . She has not hit her head or fallen, but did hurt her back and have disc injury in her lower back.