All I can say is it takes a lot of patience and consistency! You can dry covering the windows with blankets or light-blocking curtains, but if your daughter is like my son, that doesn't make a difference! Here are a couple of other suggestions to try...
1) I go into my son's room and simply tell him it's not time to get up. I go through a very, very brief version of our bedtime routine - I keep him in his bed and sing one quick song to him, tuck him back in, and tell him it's still night-night time. Sometimes it works and sometimes it doesn't. I made sure that I repeated this action with no option to get up for about a week, and then it started to sink in with him. He still wakes up, but I have noticed that he tends to play quietly longer since he knows I won't get him up.
2) If it seems like he's just not going to be quiet, I let him have a book or small toy in his bed and tell him that he needs to stay there and play for a few minutes. I only do that if laying him back down first hasn't worked.
3) I haven't personally had to try this one yet - we almost did, and then the other things started working. But, a friend of mine had the same problem with her son. So, she made sure there was a lamp in his room and put a timer on it. She set the timer for the time she was willing for him to get up - I think it was 7:00. He was told that he was allowed to get up when the light came on.
Most of all, be persistent. She's going to buck against it and probably cry the first few mornings - maybe even the first full week. It's unnerving and doesn't make for a peaceful morning, but being diligent does pay off. Then when there are relapses, it's much easier to get the routine re-established. Hope that helps some!