Agree with Shiv and Anna. The Gro-clock only works if you stick by the concept. So if she still comes into your room when the sun isn't on and gets the social interaction that she's looking for, then why wait for the clock? You want her to do it of her own volition but she's too immature for that concept. She has to know that there's no responding or interaction if the sun isn't on. When the sun is on, it's party time.
In the beginning with F, we would literally come into his room dancing and singing (I kid you not lol) - we even made up a song 'Good morning Mr. Sunshine good morning' (if I could sing you the tune I would, it's catchy) and we clapped and all got excited and started our day. When the sun wasn't on, nothing. No response, no interaction, no light, no talking, nothing. If he got totally off the wall, we would gently remind him from outside the door 'Finn, Mr. Sun isn't on, it's still night, you can call us when he's on' And lo and behold through regular consistent routine, he learned the concept. We started at 18 mths properly but even now, the thing still works. He still calls us of course, we can't control that. What we can control is whether we act on it or not.