Scenario 1: You'd never discussed the issue in-depth or imminently prior to making your relationship serious/getting married, and she mentions it to you later on in the relationship.

Scenario 2: She changed her mind from originally wanting children at the beginning of the relationship to wanting to remain childless.

Scenario 3: She discovers she is infertile.

Most other aspects of the relationship are to your mutual liking.

Would you be thrilled? Neutral? Initiate breakup talks immediately? I'm curious what your reaction and reasoning to each situation would be.