When Sabine De Barra fell into the water and was carried away by the force of the water, she traveled a good distance downstream. When she went to get out of the water, it was just two arm lengths to reach the ladder.
In the beginning of the film Louis XIV is surrounded by his children in his bedroom. One of his young daughters is wearing a very modern, 21st century 'bob' hairstyle while her sisters have very long hair which would have been correct for the period.
Sabine De Barra went directly from an important interview to doing landscaping while wearing her beautiful outfit. While wearing an expensive embroidered corset, it is highly doubtful that she would have gotten it soiled with earth. She would be change into darker clothing or cover it with a dark smock.
(at around 45 mins) Mr. Le Notre asks Sabine De Barra if she is married, something he would obviously know because she is addressed as "madame" and not "mademoiselle".