Thanks for your message.I have only just discovered that I have a Fishenden in my family.
An ancestor of mine, John Bennett, married Rebecca Fishenden, born 4 February 1806 in Minster, Sheppey, Kent.They married on 26 December 1831.
I don't know if there can be any connection with your Fishenden's - I'm sure there must be somewhere if we go back far enough.
Do you know where your Fishenden's originated. I can let you have a little more detail about Rebecca's children if you wish, but my research is at an early stage and is limited to Kent, England, so far.