Morgase's age is well known, she had kids young. Morgase has lived a comfortable life and won't look anywhere near as old as a farm wife of her same age.

Elayne is too young to have begun slowing. She herself tells Nynaeve slowing begins between 20-25 ... But in 20 years she'll probably look exactly like she does right now. Melanie could be anywhere from 30-80 for all we really know. WO live exposed to the weather and likely have shorter life expectancy due to the harsh conditions so it's very possible Melaine just looks older than her years despite slowing due to living in the waste.

Sorilea could also be much younger than Cadsuane assumes. She thinks her grand daughter's grand son is an appropriate match for Egwene ... Which could make her as young as 150 ... Assuming she had kids at a normal age, by no means proof.