How was Marguerite able to get permission for Suzanne to visit her?

Marguerite was able to get permission for Suzanne to visit her by making her invitation in front of the Prince of Wales. This formal invitation was one the Comtesse couldn't refuse.

She was expecting a visit of her old school-fellow, little Suzanne de Tournay. With all the merry mischief at her command, she had tendered her request for Suzanne's company to the Comtesse in the Presence of the Prince of Wales last night. His Royal Highness had loudly applauded the notion, and declared that he would give himself the pleasure of calling on the two ladies in the course of the afternoon. The Comtesse had not dared to refuse, and then and there was entrapped into a promise to send little Suzanne to spend a long and happy day at Richmond with her friend.