How old does she look? If she could pass for being in her 20's and she doesn't go up to the bar for any reason you might "get away" with it. But like the PP said, if someone recognizes her there may be an issue. I've heard about teens being asked to leave, them and the parents ignoring the request, and then being escorted out. I can only imagine how embarrassing that would be.
Just like in a normal club,
DCL reserves the right to ID you at any time, for any reason.
Now this is not a flame or an attack but I have to point out there is a reason DCL reserves this area for 18+. It's a place for adults to unwind and have some fun sans kids. Now I'm sure you're daughter isn't like this but I could forsee something like this happening...
16 or 17 yo in the bar with parents, doesn't get "caught"
Goes and tells one girlfriend in the teen club what she "got away" with.
That girl tell someone else who tells someone else and so on.
Before you know it you have 5 or 6 teens in there and it becomes a problem.
OR
Very intoxicated lady is having a good ol' time in the bar, unaware that there is a teen.
Teen sees this, and tells her friend in the teen club "you'll never guess what I saw your mom do last night...."