Yup, let her get dirty.

If I sent my child to daycare and they came back clean I would wonder what they're doing with the kids?

I don't mind pretty clothes, because if the parent sends them, then in my mind they expect them to get dirty. Because I have that in my policies as well.

What I hate is difficult clothes! Leggings on tiny, cute, pudgy girls. Jeans with belts! Rompers that don't undue at the bottom for easy diaper changes. And my personal "favorite" the overall. They're not in style, they don't look that cute, they're a pain for me and the child as the shoulder straps are always a concern. Why bother!