Everyone grieves a bit differently. I remember when my mother passed, it was a whole year and a half until it really kicked in and I nearly had a mental breakdown. After that, I started grieving the proper way and eventually learned to accept that life was going to be different, but that didn't mean life had to stop.

It sounds like she got herself into a relationship with you before actually taking those proper steps of grieving. Time is definitely what she needs. Be supportive, but don't push her too much. As she said, let her reach out to you.