What is the real reason April insisted on wearing false eyelashes and dressing up as an adult?
April is feeling a bit lost and unloved because she is staying with her grandmother and feels somewhat deserted by her mother. She is lonely and tells April that,
....imaging games are just about all I ever play because most of the time I never have anyone to play with" (33).
So this is a girl who doesn't have a great deal of practice in being with other people her age. And we hear this in Melanie's thoughts, too:
There was only one thing that April didn't seem to know much about - that was getting along with people (36).
She is also worried about being the new girl in school, and we are told that she has had lots of experience being the new girl in school. She is having nightmares about going to yet another new school.
Now, we also know what April tells Melanie when Melanie asks about the false eyelashes. April tells her that she wears the false eyelashes because her grandmother does not like for her to wear them. And in the same converation April reveals to Melanie that her grandmother does not believe her mother will be coming back for her in the near future.
Once we put all of that together, we can see a sad, lonely child, one who does not know how to make friends, and one who is missing her mother and who is not comfortable in her grandmother's house. She is facing a new school, as well. The eyelashes and the clothes are what we call a defense mechanism, a way of protecting herself from all the hurt she already expects out of life. In a way, it is almost as though she is putting on armour!