Cover her head?
Or was it because she didn't want to face the chador, the hejab, the burka, or whatever they use in Turkey to gag and disappear their women?
There's a telling quote in the Times article:
A picture of her at the G20 summit in London, standing next to Emine Erdogan, the wife of the Prime Minister, Tayyip Erdogan, attracted mixed emotions, however, since Mrs Erdogan’s Muslim headscarf is viewed with distaste by secular Turkey’s establishment, which fears that she creates a negative, over-conservative view of the nation seeking membership of the EU.
"I bet she decided not to come because she didn’t want to be involved with our headscarved crowd," said Cigdem, 39, an accountant. “Who would? I'm glad we don't have to watch her posing side by side with them here."
Sounds like mainstream Turks don't want to see covered women, and muslims don't want to see infidels faking it in garb.
The real question is, Will she be the first First Lady to refuse to bow to Eastern "conventions"?