Keep separate residences, and ask for full no-contact and 100% transparency*. DATE each other for six months, with a re-evaluation of how it's going at three months. (this can either be exclusively or non-exclusively, but have it be what YOU want, and be HONEST with her about it).

You'll know soon enough if she's sincere or not.

Puppy

*make sure that YOU approve the content of the no-contact letter that she writes for OM, and then YOU mail it (so that she adds or subtracts nothing). Also, make sure you have at least ONE channel of intel in your transparency system that is UNKNOWN to her.