Insiders claimed on Wednesday that Britney – who has sons Sean, 13, and Jayden, 12, with her ex-husband Kevin Federline, 41 – checked herself into the facility about a week ago, and is expected to stay there for 30 days. In January, she announced she was putting her Vegas run of ‘Britney: Domination’ at the Park MGM resort on hold until further notice due to her dad’s health. Jamie Spears underwent two major surgeries after his colon ruptured in November. Explaining her decision, the blonde wrote: ‘I don’t even know where to start with this, because this is so tough for me to say. I will not be performing my new show ‘Domination’.’