As someone who actually does like and use the subjunctive, I'd say no too. Only if you know that she was in fact enjoying herself and "not enjoying herself appearance" was therefore counter-factual would the subjunctive make sense.
That Mona. What a great actress. She's been texting me all night saying what a great time she's having, but there she sits, looking for all the world as though she were not enjoying herself one bit. It's so she can make her boyfriend, who insisted she come to this party, owe her one.