What would you do if your life partner just one day tells you that they are moving out because they need time to think. She tells me she is not sure what she wants anymore and living apart will help her decide.

I did not see this coming, any ideas on what to do?

No one has any ideas...

You should give your spouse a time and space to think about it. For sure there's a big issue / problem that she thought you and your spouse can't handle it. Giving them a freedom is the least option for him/her to think more what she/he wants and if she/he's ready to give up.

You should be calm and try to talk to her. You should let her/him feel that you care and love her. Don't let her/him think that you are willing to be apart from each other. Try to convince her/him to settle things as much as you can.