Dear Sureeporn,
Thank you for your inquiry. We sincerely welcome you to join the conference.
We could definitely arrange all four of you in the same session. We could try our best but not promise the exact time you have specified however. The session will be adjusted according to the overall participation at the end of December. Please kindly allow more flexibility to your travel schedule in advance.
If you have any question, please feel free to let us know.