You should have told her that it is her gift for Mother's Day. There are plenty of items being sold at the store, so there is no way for her to know what you got her. If she decides to visit the store or website to see what you might have gotten her, then that is up to her to spoil the fun. It would have saved you from being grounded over such a simple action.

Why didn't you just say "it's your mothers day present, I can't tell you". Seems like that could have been easily avoided.

I absolutely despise parents who ground their kids over minor things. Grounding a kid has to serve the purpose of raising them right - not personal revenge or blackmail when the kid doesn't satisfy their parents' curiousity. Kids are people too, they're allowed a little privacy, as long as the parents don't have informed reason to believe something bad is taking place within said room of privacy.

Tell her that it is her Mother's Day present. I mean is is that hard not to figure it out. It doesn't spoil anything.

doesn't she know the word "privacy"?

You didn't have anywhere else to put it?

It is a difficult situation the mother was put in. I was grounded in a similar situation when I kept a secret that her friend asked of me. The way she sees it by not telling her what it is that's the same as lying. As a parent I understand where she is coming from but I agree with most here and that OP should tell mom its a surprise.

I hope you showed her what it was, and then trashed it. After all, you can't give her a present when she already knows what it is ;)

You should have said "I can't tell you because it's your Mother's Day present." I'm sure she would have understood.

you should have tell her it was a secret or make up something :/