It won't hurt to submit a sample. Blood relatives are often not compatible while strangers might be.

They might not want your kidney, though, they prefer a much closer age match.

Still, it doesn't hurt to get tested. Thank you for the generous thought.

You might be considered too old.

You also need to be her same blood type.

Tell them you're interested and see what they say.

I hope you can help!

I doubt it would work since you are not blood related but it would not hurt to be tested.

Sometimes unrelated people can get pretty close on matching... =They have gotten a little touchy about these things with people in our age group, some Drs. are more so than others, I had a surgery a year ago that a friend of mine who is only slightly older was told he was too old for.. so depends on Dr.

using Who is eligible to donate a kidney, and of course got various hits.

This one looks reasonably helpful: http://www.transplantliving.org/living-donation/being-a-living-donor/qualifications/

It does not look like there's an upper age, so long as everything else is good.