@Ducky. Try reading that list of negative symptoms again. She's showing most if not all of them in this chapter.
On the current page she's specifically stating "I will try to go make friends then" in a seemingly flat tone with an expressionless face.
Like I said, I can give you the flat affect... but the rest?
lack of emotion - the inability to enjoy regular activities (visiting with friends, etc.) as much as before
I've seen no evidence whatsoever that she does not get enjoyment out of her life or the activities in which she chooses to partake. Yes, she does not enjoy the activities her mother would like her to enjoy, but there's no evidence that she doesn't enjoy the activities she does.
Low energy - the person tends to sit around and sleep much more than normal
Again, no evidence of this. When have we been shown that she is lethargic?
lack of interest in life, low motivation
She is so interested in life that she wants to discuss the meaning of life with her mother.
Alogia (difficulty or inability to speak)
She seems perfectly capable of having rational thoughts and communicating those thoughts through speech.
Inappropriate social skills or lack of interest or ability to socialize with other people
You could maybe argue this one, but it seems less like she doesn't want to, or is unable to, socialize with people and more that she might be a little shy or (as stated in the most recent comic) she doesn't feel she has anything in common with other children.
Inability to make friends or keep friends, or not caring to have friends
See above.
Social isolation - person spends most of the day alone or only with close family
She doesn't spend all day isolated. She goes to school.
I could see arguing for maybe 2 of the negative symptoms, but even then she is not meeting the criteria for a schizophrenia diagnosis. The negative symptoms alone are not enough, she would have to have at least one of the positive symptoms in conjunction with the negative ones. Additionally, I feel it is more likely that she is simply socially awkward or has something else going on, or that she just doesn't know how to relate to people, rather than being schizophrenic as there is absolutely zero evidence for any negative or positive symptoms in adult maytag.