While her husband David Rose was getting coffee, Audrey Rose scribbled a note to the flight crew and handed it to them as they boarded the plane.
During the flight, the pilot came over the speaker and made the announcement.
Audrey had found out she was pregnant the day before the surprise but wasn't entirely sure.
She got up extra early and tested positive again, and then made her plan to surprise David.
Audrey is pregnant with the couple's second child.