Well, since Estelle is "only" the daughter of the Crownprincess and not of the King like Victoria was during the time of her baptism it might become a much smaller baptism ceremony.
Besides: After all those strange occurences (announcing on February 2nd the child won´t be born before early March, announcing the birth at 7.00 a.m. where everybody was still asleep, stealing away with the baby through the rear entrance, giving a ridiculous name like they wanted to make clear: "Hey if we will call her Donald Duck then it´s not your business, and besides, we don´t care whether she will be Queen one day...") I sometimes believe they might appear in Jeans and Sneakers and baptism her in Öckelbö....