I think that the origin comes from porn. The idea is that the girl is so small that she can spin around while doing CG. There isn't an agreed definition, but to most people it definitely entails being slender, short (e.g., 5'3" or less), and usually very young. Definitions differ, so perhaps guys should be more precise when asking.  

To me, you would fit the spinner definition based on height and weight. However. the sophisticated Venetian lady living in London that is reflected on your website isn't really in line with the spinner idea. I think that you would be in more of a courtesan or possible long-term GF category.  

For what it is worth, I would be far more interested in seeing you than anyone fitting the spinner stereotype the next time that I am in London.