Bless her soul for baring incredible honesty, for all of us to understand.
For a while now, since experiencing some of these awkward moments myself, I've made it a personal rule not to ask these inappropriate questions:
"Why are you single?
"Are you seeing anyone?"
"When are you getting married?"
"When are you having a baby?"
"When's the next one coming along?"
See also a reader of elegantwoman.org's similar situation.
Let's all be sensitive to women who are unmarried (no matter what age) and childless.