As for me, I'm attached and yesh, most of the time I still go
out with guy friends with acknowledgement made to my bf that I go
out with this or that friend.
Whether is she gaining attention dis I can't comment much
first u know she's attached, so from what u written, I assume u
like her and wish to further the line between u n her.
But first are u sure she wants to cross the line?
if you think it's a waste of time if everything just remains as a
platonic friendship, why not tell her so if you wish to? No harm

In anyway, some girls just dunno how to reject a guy 