Just finished playing through it. No its not free, no she's not fleshed out (another Zaeed, but still not as bad). IE, she has no 'direct' dialogue between Shepard & herself (recruitment speech aside).
BUT, do not dispair all that much. Her loyalty mission is really really fun. (One of my new favourites). & the room she is in (Starboard Observatory on Normandy) has A BAR!! (stupid, I know, but it really adds a pimp feel to the Normandy)
& she's hot (physically, emotionally & just in a cool way). She has some real bad-ass moves. (A pretty much instant-kill, flashbags & overload).
Meh, for a few hundred BW points, totally worth it (IMO). Just adds a few more fun minutes into an already fun-packed game.
No, not an essential download, but if you have points to spare/don't care about price, she's a cool addition to your team