Hannah is certainly older than Ian, being a biblical (Old Testament) name. Ian appeared in Scotland many centuries later. According to one reliable source, Ian was not used until the late 19th century.
Hannah has the Hebrew meaning, "grace."
Ian is a Scottish form of John < Hebrew Yochanan, "God is gracious."
So while both Hannah and Ian contain the element meaning "grace," they are not otherwise connected, and the answer to your question is no.
I suppose any feminine form of John could be indirectly considered a feminine form of Ian; for example, Jane, Johanna, Joanne. I believe that the forms typically used in Scotland were Jean and Jessie.
This message was edited 3/5/2012, 10:33 AM