Sorry I missed that. The spelling of her name in the 1850 census is
Chelsie and in the 1860 census is
Chelsey. So yes, she is an earlier example than the one I found while writing my column.
I am not sure why a battle in Massachusetts would inspire these names in Connecticut. I think they are more likely linked to
Chelsea Landing and
Chelsea Parade, two historic neighborhoods within the city of Norwich, Connecticut.