Mother May was born in 2236. She is 41 and Confessor Cromwell's female counterpart. She and Cromwell are actually husband and wife, but they don't go out of their way to advertise the fact, because they're both so busy promoting the ideals of church.
Maya is the wife of Confessor Cromwell. Even though this makes her 41 at the time of Fallout 3, she appears to be elderly and in her 70s, most likely from the exposure to radiation, prolonged exposure to sunlight, and lack of clean drinking water.