The correct answer to this open question is the following.
Although you did not attach options for this question we can say the following.
My diagnosis is that Kristin is having panic attacks because she is in a continuous state of uncontrollable worry and tension. So she has a panic disorder and it is recommended that she goes with psychology immediately.
Kristin worries about her family a lot due to her family situation at home.
Then the symptoms are the following. Kristin is having trouble concentrating on her studies and has been complaining about various physical problems. She has sudden, unexplained attacks of fear. Sometimes, for no apparent reason, her heart races, she has chest pains, and she gets sweaty all over. On other occasions, she feels nauseated and dizzy. She went to the doctor because she thought she might be having a heart attack, but despite the symptoms, her heart was fine.
So yes, Kristin is having panic attacks or a panic disorder because she is in a continuous state of uncontrollable worry and tension.