Kristen is only going to take one of the jobs. Since she had already told Marshall's that she would accept their offer, when Chick-fil-a also offered her a job, Kristen was distressed that she would have to call the people at Marshall's back to decline.
She doesn't enjoy talking on the phone at all!
But she gathered up enough courage to make the call and then to accept the offer from Chick-fil-A.