For the past few weeks DD has been trying to stay up later and later because it is so light in her room. So this week I bought her blackout curtains. We have been using them for 2 days now and she is sleeping longer and better. For the past 2 days she slept an hour longer in the morning yay! They were not cheep but I am so glad that we finally broke down and got them. Well worth it so far.
Re: why didn't I do this sooner!
I got Pottery Barn Kids blackout curtains off ebay.
They work wonders! I was also told about black out film you can put on your windows. Similar to this but i got it at Lowes. They carry it at Home Depot too. I got some because while blackout curtains help a ton, light still comes through. Plus her room just boils.
I got mine at Walmart. About $6 each. They are like this one:
https://www.amazon.com/Redi-Shade-1817205-Pleated--72-Inch/dp/B000SDTEAG/ref=sr_1_14?s=home-garden&ie=UTF8&qid=1370057099&sr=1-14&keywords=blackout+curtains