I used to wait until December 15th, too but having my twins prematurely when I did gave me the extra leverage to say, ' but I missed a Christmas! I've got to make up for it!' haha This year I will have the tree up before I open the first door on my advent calendar hehe
I haven't decided yet, whether to let my little girl help me and do it together, or to do it when she is sleeping so it's there as a magical surprise when she wakes up... Last year we did it together and she loved it but I imagine it would feel magical to go to sleep and wake up to a twinkling Christmas tree
Yes, this year mine will be up before the end of November. I would suggest setting up the tree without your daughter, but saving a few "special" ornaments for her to hang!