I've always loved a well broken in glove. I see posts here saying they are worn out if they lay flat. Is this because kids don't have the strength to hold the glove open?
I have seen kids with flat gloves and every time the ball was hit to them they would fumble. The kid was all over the ball, but she is already handicapped because of her glove. I couldn't bring myself to tell her dad. He seemed to know everything already.
You should see Eric Hosmer's (KC Royals) faded blue glove. He tried a new glove out after a ball went through the webbing, but he has had blue one re-laced several times and continues to use it. If you see it on TV you know it is pretty close to the equipment manager doing a mandatory retirement on the glove.
If your DD is still effective with her glove get it re-laced and play on. One players worn out glove is another players slightly broken in glove.