When I were a lad there was a Mother Hubbard's in Oldham and AFAIK it was the only one. Closed in the late 80s I think. Site had been all sorts since then, until some time in the 2000s when it reopened as Old Mother Hubbard's. I didn't realise it was a chain though - just assumed it was someone resurrecting a local institution that people still referred to the site as.
ETA - having looked into it I'm still not convinced that even the current one in Oldham is part of the wider chain. Has a different web page