"Well, that's nice of you!" Really? What am I, a friendly acquaintance?
Easy does it! (See? I use exclamation points all the time.) Correct usage? No, but maybe she was trying to show her pleased feelings through a text....which if very hard to do!!! Then, maybe she wasn't, but why go off like a cannon? It's just as easy to think she like it, rather than think she was being nasty.
Just calm down or you will never pass your part of the test.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!