D.W.
That part takes grace, grace, and more grace. They are frightened by the experience and have nooooo idea what to do......until they have success and support. I suggest that you be there to enjoy the successes and make it is easy as possible. I love the suggestion of figuring out when she needs to go. How I started with my first one was to try before we left the house and immediately when we got back and that would be about a good two hour span of time.
All the best. :)