Football is a dangerous sport and she knew that was the sport (and career) for Tom Brady.
Even before we started to learn about CTE, we've known that it's risky to play football.
Obviously, she shouldn't have married him if she was uncomfortable with the risks he was taking.
At some point though there’s a line. How much risk do you really want your loved one to go through. Jackie Stewart has talked about the day he and his wife sat down to count funerals, how many of his fellow racers had died. And they both got scared and he didn’t finish his next before he decided the risk was too high.