From chess-news.ru:
Grandmasters Alexandra Kosteniuk and Pavel Tregubov have legalised their relationship. This became known via Sergey Karjakin, who wrote about it on Twitter, whilst on his way to Chita for the Russian Superfinal.
It is the former wold champion’s second marriage. Her first, to Swiss/Columbian Diego Garces, was well-known at the time, as tthe two met when she was just sixteen and he was 25 years older and they married when she had barely reached adulthood.
Several years later, they had a daughter, Francesca-Maria, and 18 months after that, Kosteniuk became women’s world champion, when she won the knockout event in Nalchik.
Pavel Tregubov is a Russian GM, who has lived for many years in France. He is also older than Kosteniuk, although this time the age difference is not so great – just over 12 years.
Source: http://chess-news.ru/en/node/19713