So, it depends on the information you have available. For England, the counties are the "admin entity" and in the US, this is states. Selina appears to be from Lancashire and ended up in Massachusetts, so that would be [[Category:Migrants from Lancashire to Massachusetts]]. If she lived in another one of England's counties and migrated from there, you would use that county instead.
Here is a handy tool: http://mcg.harrislineage.com/index2.html
Just fill in the country and "admin entity" and it will give you the category to use.