What is the explanation Nausicaa offers to her father, when she is going to the river to wash clothes?

Basically she says that she wants to wash clothes. She says that he is an important man and thus needs clean shirts for council meetings. She also says that her five brothers need clean clothes when they go out dancing,

"Papa dear, could you manage to let me have a good big waggon? I want to take all our dirty clothes to the river and wash them. You are the chief man here, so it is only right that you should have a clean shirt when you attend meetings of the council. Moreover, you have five sons at home, two of them married, while the other three are good-looking bachelors; you know they always like to have clean linen when they go to a dance, and I have been thinking about all this."

Her father gives her the cart and mules to make the journey.