Don't tell her until you're moving and/or need to make changes re taxes. Be professional and tell her only what she needs to know as our employer.
In the meantime do your job and don't bring your personal stress to the workplace. That way, by the time you tell her you'll already have demonstrated your ability to do your job well regardless of what is going on in your personal life.
Don't get personal w/ your MB, especially this early in the relationship. It doesn't matter if she's divorced recently or is empathetic or whatever. Just do your job and don't make your problems a problem for her in any way.
MB