Pamar, its great that she is opening up to you about what is bothering her. She could just have been in that sour mood and said "Nothing's wrong" or worse, started a fight with you. I think she is feeling crowded at work by this unwelcome advance (albeit you said he is a nice person, just likes your W). You did everything right.
"As if" tonight and just be very friendly and helpful. Tell her you hope she is feeling better. I think even as great as its going for you guys, it'll still be a bumpy ride from time to time.
