[DavidByrne]

I'm descended from Robert "Cavey" (Carew?) Cottrell, and my researches suggest that there may have been three siblings - Henry Jr, Robert and Charles. Having said that, proof is hard to come by!

Carey, as you may know, is often considered to be a form of Carew. Robert's middle name is potentially the only real clue as to Mary's origins, whether it's Carew or Carey. Attempts to find a Cavey connection have drawn absolutely no result.

And I agree - taking info from published family trees can be like the blind leading the blind.