My niece used to say she believed in Santa at 13. She's now 24 and while she does function as a grown-up, she openly says she misses childhood and doesn't like having to "adult".  I think it's a way for kids to avoid growing up. 

Idk about the santa thing... but I can see her wanting to go pick out pumpkins.. esp if she is a halloween fan.  I see no reason why dad can't take her to pick hers out.. 

She knows there is no Santa, but hey her saying she believes at least makes it plausible for your toddler. Spawn and BS were much older than BD, but they continued to "believe" in Santa until BD was old enough to figure it out that he wasn't real.

Your SD is obviously playing it up for attention. Probably because you have a toddler and it's giving her some insecurity.

Did her parents split up when she was seven? I have found that CODs a lot of the time get emotionally stuck at the age that their parents split. This is very much due to the parents treating them as if they are still that age because they themselves are stuck. This is especially true of non-custodial parents because they interact with the kids a lot less so they don't update their expectations for them.

My husband used to do this with SD period in his mind she was forever 4 years old. He did update his expectations once she became about 10 and stopped being into "baby stuff" and asking for toys intended for much younger kids. 

Yes, Virginia, there is a Santa Claus. He exists as certainly as love and generosity and devotion exist, and you know that they abound and give to your life its highest beauty and joy. Alas! How dreary would be the world if there were no Santa Claus! It would be as dreary as if there were no Virginias. There would be no childlike faith then, no poetry, no romance to make tolerable this existence. We should have no enjoyment, except in sense and sight. The eternal light with which childhood fills the world would be extinguished.

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Maybe remembering Santa Claus is a comfort to them?? 

If she was saying it around your toddler to make sure they still believe then ya ok. Stating that she actually thinks he does.. then it's attention. 
 

SD13 has a "friend" (I am friends with her mother and I don't know how she deals but that's another story) but, we took her to the beach this past summer and she was telling SD she was a mermaid and causing the waves and bunch of other ridiculous things. Legit was trying to claim she was a damn mermaid. SD was like uhhhhhhhh noooooo. 

SD and this friend are drifiting apart because they are two totally different people and I feel so bad for friends mom.

Also though, SOs friends kids DID actually believe the elf on the shelf was real for a little longer I think then they should have... not at 13 though. Around 11. 

I do not see the problem with a 13yo sustaining the fantasy of Santa Clause.  Every year when my family gets together for Christmas we all give gifts to each other. Some from us, some from Santa.  The point is to enjoy the holidays toghether.  Why can't that include Santa Clause?

My son is 28, my brothers kids are 26, 21, and 18.  Everyone reads the gift tags and opens gifts from Santa every year just as we open gifts from each other. Each of us happily thanks Santa for the gifts labeled as being from Santa. Then of couse we hug hte person it was actually from.   The kids all do this being in their late teens to late 20s,  I do itt at 56, my wife at 44, my brother at 50, his wife at 52,  and our parents at 75 and 78 respectively.  For us it is a tradition that has has stood out for generations.  Do any of us "believe" in Santa.  Of course not. But everyone one of us believes in the joy that the trandition brings to everyone in the family.

I have always been mind boggled by the tendency that so many people have to destroy the joy of others during the holidays.

I remember in 4th grade having Kinder reading buddies that we'd meet with. We helped them write a letter to Santa then in class, we responded pretending to be an Elf. This was something the entire class participated in and many of whom were very religious as I went to a small rural, farm kid elementary. No parents made a fuss and no kid had their belief stomped on by this activity. 
 

At that age, she is definitely playing that she still believes. Maybe she thinks she won't get gifts and a stocking if she doesn't participate? Or maybe she's doing it because she thinks you guys like her to? 

I'd profess to believe in Santa if I'd get spoiled rotten on Christmas!  

no it will be an act!  My exSS13 is the same , still 'says' he believes in santa but is quite happy to tell mummy and daddy what he wants for xmas , tells them where to buy it from etc.  I say your SD will pick and choose when she wants to believe.  I understand wanting to go pick pumkins for Halloween ,, i would want to do that too and im 37.  Its all an act to keep the focus on her and her still being daddys little girl.   What would she do if you straight out told her santa isnt real?