Depends where her thoughts lead her. Do something sweet send her flowers love note something simple but great to her. Like hand write her a note asking her to come on a date with you and take it to her work and tell someone she knows to give it to her
It does not necessarily mean you are about to be single. You just have to let her think it through and get to articulate yourself well. It also would depend on the gravity of the issues she is going to think it over. Analyze critically the situation and you will know if she is actually leaving you.