Hi OP,

Here's a suggestion you might want to try that motivates many children and is easy to adapt to different circumstances:

Colorful wooden beads with a hole through the middle to put on a key ring. You can buy them at craft stores.

Make sure she understands the rules.

You put a certain number of beads on a big key ring....maybe 3 for going to the store.

You tell her each bead is worth (whatever you decide) maybe 3 chances.

If you decide 3 chances, the first time she misbehaves, you tell her no but don't mention the beads.

She does it again, you say I already told you no, this is your first warning. You have two left before you lose a bead.

She does it again, you tell her, this is your second warning. You only have one more before you lose a bead.

On the 3rd warning, you tell her she used all her warnings, next time you'll be taking a bead. If she does it again, tell her she used up her chances now you get a bead and remind her she now only has two on the ring.

Any crying, tantrums, automatically takes all the beads. No more chances.

She gets to carry them when you go out. She knows ahead of time that if she can have one bead remaining by the time you leave the store, she is rewarded with.....Stickers, bubble gum, a fast ride on the cart on the way out, one of those junk rings in the machines by the door, whatever.

Make sure to tell her she made you proud by working so hard to keep a bead. When she starts keeping more beads, or losing none, keep letting her know how proud you are of her hard work.

If it's effective, you could have her put a mark or sticker on a chart when you get home and when they add 6 days, she earns a Happy Meal...or whatever.

It should be a "game" that she's working for a goal. It can be easily modified by using different amounts of beads, different amounts of chances, etc. but if you start high, then decrease them, let her know it's because she's such a big girl and getting so well behaved that you don't need so many.

You might even use 3 beads when you go away, but 5 or 6 at home.

Just make sure she understands the rules even if you have to have a practice at home to make sure she understands.

It's amazing how much kids want to hang on to those beads.

Good luck. She's lucky to have you care! Hope you'll let us know how it turns out.