CB...I will chime in. I took my ring off about 2 weeks after BD. I have not put it on since and it didn't feel right wearing it. It is a personal choice but for me it signaled that I was still hanging on.
We always put the tree up together as a family and decorated it as well. This year I will not be inviting my W over to decorate the tree. That is something I will do with my D's. If she wants to put a tree up and decorate with them in her apt then she can go ahead.
I did extend her an invite to be at the house in any capacity she wanted to. I will have the kids on Christmas Eve and Day so because we both agreed that they should wake up in our home and not her apt. I told her she was under no pressure or obligation either way, I thought it would be good for the girls. I personally have no expectations. So far she has indicated she wanted to do something together as a family on Christmas eve but is not sure about anything else at this time.
I am a little farther down the path than you so please take that into consideration. IMO you need to be in a good place emotionally and if she accepts you can be happy around her, not pursue, etc. TBH I could not do that early on so if I was 1 month in I probably would not have been able to handle it. I hope this makes sense.
If your in a good place emotionally, know you can hold it together, etc and you feel that you are doing it truly for your children and being a good co-parent I do not see anything wrong with it.
I would probably feel different though if OM was in the picture and I don't think there is at this point in your sitch or at least you have not discovered 1 yet. I have not discovered one yet in mine as well.
