What does Sheila promise to take off from the booklet in Judy Blume's Tales of a Fourth Grade Nothing?

In Chapter 7 of Judy Blume's Tales of a Fourth Grade Nothing, Sheila agrees to take off the line she added to the cover of their booklet that reads "handwritten by miss sheila tubman."

In Chapter 7, Peter has been assigned to work on a group project with two of his classmates who live near him, Jimmy Fargo and Sheila Tubman. Their project is to make a poster, write a booklet, and present an oral report about transportation in New York City. At one point, they agree the boys should each write five pages of the booklet while Sheila does the other ten. Peter raises the concern that, if this is to be a group project, all the handwriting in the booklet should look the same—it shouldn't be obvious which kid did what part of the project. Sheila agrees that, since she has the best handwriting, she should copy all of their written work into the one booklet.

On the day Sheila makes the cover for their booklet during one of their after-school meetings, Jimmy notices that, though Sheila put all their names on the cover of the booklet, she also gave herself special recognition by identifying herself as the one wrote the booklet by hand. Jimmy and Peter are furious because they had all agreed that, if it was to be a group project, they should each get the exact same credit as the other members of the group. Sheila objects at first, but when Jimmy threatens to rip up the cover, she finally agrees and turns the line that reads "handwritten by miss sheila tubman" into a decoration of "sixteen small flowers" (50).