What should I get my girlfriend for Christmas?

I've been dating this girl for 3 months now and I'm just so lost at to what ti get her for Christmas. I got her a necklace already from Tiffany and co but I want to get her something else too. she performs for our high schools guard time, favorite colors blue her are blue she's funny always makes me smile, likes fireplaces and peaceful places likes cookies and cakes shes cute and just amazing so I'm baffulled for what to get her. Help please present ideas