I don't know why she offered to do the chest compressions, but at least this is a big learning experience for her, that if she's going to work in this department, NO, you can't let you past trauma upset you/affect you and instead you need to overcome it to help others in a similar situation.
And if she can't, she's gotta get out of ER
May be harsh, but she can't work there if this kind of situation were to happen again
I hope he also learns why she was so affected by this :c