Hello, Monica, thank you for putting it up.
I've also seen you made a list of all the pieces on this suite; however, this one's title is "A manha da Pierrette", and not "A manhã da Pierrette" (the tilde makes all the difference!). Therefore, the correct translation is not "The Pierrette's Morning", but "The Pierrette's Ruse". That is important for interpretation purposes, setting the general mood for the piece. I'd covered this in my previous post of this song:
Now, that's a pickle to translate. "Carnaval", although usually translated "Carnival", has nothing to do with amusement parks: rather, it is a street festival we have in Brazil, more or less in the spirit of the Mardi Gras, and around the same time. Today carnival is a festival mainly for adults, but a long time ago it used to be that children would also go out during carnival, wearing several different costumes: Pierrot, Colombina, Arlequim (look them up!)... Like halloween in the U.S. In some places children still do go out. Pierrete would be a female "Pierrot", a traditional costume worn during the carnival.
And "manha" would be something like a caprice, a whim, or a ruse, slyness, artfulness.