That's very interesting, Australian. Thank you. I have some doubts about this though. It's a known fact that artists don't always represent exactly what they see. It could be symbolic for so many reasons (i.e. the child she never bore - the 'loss' of not having a child, etc). It reminds me of the debate over Van Eyck's
"The Marriage of Giovanni Arnolfini and Giovanna Cenami". People say that the female figure is heavily pregnant at their wedding, while others (including me) disagree.
http://www.nationalgallery.org.uk/We...186/eNG186.jpg As EmpressRouge said, it's more likely to be a figurative representation not a literally one. There's probably some religious references too (Virgin Queen, Virgin Mary) but that might be a long stretch.