We don't keep her around for her secret keeping abilities

This morning Tom and I split up to do some shopping. Tom took Reese as they both had presents they needed to get for me and Donovan (respectively). I told Tom what Reese should get Donovan so when we all got home at roughly the same time I was very interested to see what she had bought Dono. She has been a good secret keeper before with Tom's birthday gift she helped me pick out so I had high hopes. I waited until we were out of earshot of Donovan and asked her what she got Dono. The following was our conversation.

Me: whispering "Reese, what did you get Donovan for Christmas? Say it quiet so he doesn't hear. Remember it's a secret."
Reese: "We got him a watch?"
Me: (surprised as I had told Tom to get Donovan an action figure) "You bought Dono a watch?"
Reese: "No, we bought you a watch" (It was on my list and made much more sense)
Me: "Um, Reese, that is a secret, you aren't supposed to tell me that. What did you get for Donovan?"
Reese: "Nothing."

So I ask Tom if he really didn't get him anything and Tom reassures and shows me they got Dono a spiderman and a batman (and I broke it to him that I know I am getting a watch). Then 10 minutes later the kids and I are downstairs looking for old stuffed animals to donate to the humane society and Reese shouts. "We got Donovan a Spiderman at the store". Donovan of course hears this, looks at me horrified like he doesn't know if he is in trouble now that he has heard his present and I try to shush Reese and tell her to be quiet. She proceeds to shout, "WE GOT DONO A SPIDERMAN!!!!" approximately 15 more times. I tell Donovan to put his hands over his ears and not listen, which he did, but then told me he had already heard. I kept telling her it was a secret and that she was not supposed to tell Donovan and she just kept insisting, "But we DID get him a spiderman."

About 20 minutes later all 4 of us are in the car on the way to lunch and Reese says again, "We got Dono a spiderman, HAHA!" Tom and I laugh because we are caught off guard by her Dr. Evil laugh and we tell her that she shouldn't say that as it supposed to be a surprise. She didn't care. She told us, "But it is funny!" So now she thinks telling secrets is funny. She is a mess. At least she didn't remember the batman so Donovan will have one surprise at least.