Image of Medieval crypt carving needed

Here's a few to get you started:

http://www.nipissingu.ca/department/history/MUHLBERGER/2006/09/funerary-brass-sir-nicholas-dagworth.htm

http://medievalwriting.50megs.com/exercises/stafford/stafford.htm

http://www.mbs-brasses.co.uk/brasses_slabs.htm

http://www.britishbrassrubbings.com/brassindex.htm

http://www.medievalgenealogy.org.uk/sources/brasses1.shtml

Some search ideas if you need to go further:

Funerary Brass

Monumental Brass

Brass Rubbing

Phil

I noticed your post yesterday and noticed also that no one replied.
Fact is that you can find those bas-relief in almost any church in england; so without further hints it might be impossible to find anything.

One famous sarcophagus is the one of prince Edward ("The Black Prince") in Canterbury Cathedral:

In this case it's not a bas-relief but a brass statue. I doubt your mother's friend could have done a rubbing because it's behind bars so probably it's not what you're looking for.