Thanks for writing to DoctorSpring.com with your health concern.
THere is no risk in travelling by a one hour flight.
If the pain recurs or persists, it is best not to undertake the journey till she is completely alright.
Also, once before travelling, it is better to get a repeat ultrasound scan to be on the safer side.
If the flight is delayed for some reason, she should walk across the aisle every 20 minutes or so.
Also, it is important to take a lot of fluids while travelling anywhere.
She should avoid eating food from outside, and carry home made food.
Also, while travelling in cabs to and from the airport, put on the safety belt and avoid jerky , fast travel.
Avoid lifting heavy weights, bending, or straining.
SHe should be fine.
All the best
Please feel free to discuss further.