Since you are friends now, don't give her something that directly reflects your past. This will avoid unnecessary trouble and affect the development of your relationship.
You can give her a beautiful digital photo frame. Put her photo in it. The photo frame must be exquisite, and girls will like it as soon as they see it.
Sending flowers is also good: of course you have to understand that you are no longer a couple. Don't give her red roses. You can choose hyacinths, violets, lilies, baby's breath, geraniums, etc.
In addition, giving cards, lifelike dolls, bracelets, etc. are all good.