I am so sorry for your pain and loss, Christine, especially during the holidays. I can understand your reluctance for celebrating, even though you have another daughter.
There is pain for any loved one we lose. I lost my boyfriend early this year and it has not gotten easier with time. I do not feel like celebrating, even though I know he would want me to, as well as his family. There will be a gathering anyway, and perhaps doing this does honor him, because I know he would not want us to feel so much pain but to enjoy the time we have with our loved ones who are still living.
Know that your daughter's bright and loving spirit is with you always, and if you choose to celebrate just a little bit it would make her very happy. I do believe our deceased loved ones are still aware of us, and I don't believe they would want us to suffer. It is hard to act happy when you are not happy deep inside, but we have to find a way to go on, in our own way and in our own time.