Uhm..... I think that is more about her existence is real right there rather than her being for her "commander". Well, It's not of much different in Japanese, but due to the circumstances it's said in, the meaning may varies after all. Though I can't be too sure of it.
Especially considering that all of her lines on the top of the next page end in じゃない as well.
Was there a girl like her around these parts?Aaah... I get it... I'm hallucinating things.Who.. who's she?Wait, first of all, how did she get into my house...I guess I must be tired... too many shifts this week and all...I'm actually here, aren't I!!Whoa!?