Is my mother's Wudu valid if she performs it on moisturized skin due to daily massages for strength and circulation following her stroke?
If the oil on the skin does not form a layer preventing water from reaching the skin, then Wudhu on it is valid, but if the oil on the skin has formed a layer preventing water from reaching the skin then Wudhu will be invalid and she needs to remove that layer by washing it then perform Wudhu.
Wassalaam