Hope it's not too late

[what next?]

On Wednesday I am taking the dirt over to our house and my sister has come up with an idea that I need to ask you guys about.

While we were married we never set up a Christmas tree. In the beginning my wife would do small decorations but that faded and I always thought that we would just wait until we had kids to do something like that. My sister thinks that while I am over there putting the dirt in I should set up a Christmas tree for her. Would this be pursuit? Is this a bad idea? It would be a 180 but maybe seem fake to her? Idk... I REALLY don't want to do the wrong thing but I think it could go over well. Not really sure... guess that's why I'm here