I do know in the late 1700's there was a Samuel Poucher who was a baker in Hanover Sq London he had 2 daughters but was widowed. It is possible that one the of the daughters is responsible for the passing of the name. I will have to dig up the daughters names somewhere in my boxes of info. Purhaps if we can see who they married it may be easier to work forwards instead of backwards.
I will get back to you