Okay, so back to your daughter. Watch her carefully. Ask yourself if you have noticed any significant changes in her appetite, sleeping habits, energy level, and academic, and/or social functioning. If you have then you should speak to her with empathy and calmly and ask her what she is feeling. Validate her feelings. Please don't tell her that she has nothing to be distressed about. She will experience that as invalidating.
If you are concerned that she may be depressed because she meets the criteria described above then get her to a therapist soon. The less entrenched the depression gets the easier it will be to treat. In therapy, she should learn coping skills and strategies that she will benefit from all throughout her life.
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