It depends on what you are asking. If you choose the BFF bump, then your tamas will only get a piece of jewelry.
If you have already bought all the jewelry in the shop, you CAN buy more. You could either give them away or just keep them.
If you don't know how to buy jewelry follow these steps:
1. Go to the door icon
2. Press shop
3. Press jewelry
4. Buy one
5. Press the C button (Very right)
I, being a owner of 2 Tamagotchi Friends, have never just got a piece of jewelry out of the blue. Maybe something happened?
If you are tired of still having collected all the items, you can reset. There are two ways to do this:
1. Take out the batteries, put them back in, and push reset
2. Take something that's long and thin, then look on the back on stick it into the big hole on right right for 15 seconds, then pull it out, click a button on your tamagotchi, and press reset.
Hope this helps!