Had a pin prick at the tailor while she was fitting my dress, any risk of hepatitis c transmission ?

No: Sharp object cannot transmit disease unless there are fresh germs on such sharp objects from pricking an infected person just prior to pricking an uninfected person. Even if that happens, there would have to be deep enough wounds on both people, and would have to be a high enough number of infectious germs on the sharp object to transmit a disease. That means no, it doesn't happen that way.