J.S.
She is old enough now where she'll notice what you buy and remember it when she unwraps her gifts. I know that from experience! Here are a few things I did after one botched trip with my son last year:
*Do your homework-know exactly what you want to buy and where it is before you go out. This way you can be quick and throw things in your cart without her noticing.
*If you are shopping with a cart, give her a book or small toy to distract her with while you slip things into the cart.
*If you are someplace like Target or Walmart, grab a big towel to put in your cart, so you can keep the goodies underneath it until you check out.
*Try and quietly tell the cashier not to talk to your daughter about the toys (cashier did this to me last year-got all friendly with my son after I did such a great job of distracting him and asked him who all these toys were for).
*If you are shopping at the mall, use a stroller with an umbrella-you can put things on top of it without her seeing! This only works for smaller things:)
Good luck with shopping!!