You will encounter a variety of characters in your adventure in Animal Crossing: New Horizons. You can invite several of them to join your island, save them from shipwrecks, or visit them on theirs. One particular individual you can have visit your island is Celeste, Blathers’ sister, a returning character to the series.
To meet up with Celeste, you have to wait for her to show up and progress through the game as you usually would. You have to wait until night arrives in your game, and you can randomly find her wandering around your location. Run up to her, and she’ll provide a brief explanation of who she is, her relationship to Blathers, and that the evening will have a meteor shower, which means you have the chance for a shooting star to happen.
Now, by speaking to her, Celeste breaks down how you can wish upon one of the shooting stars in the sky, and she provides you with a DIY project for the magic wand. You can create the magic wand by collecting three-star fragments and one large star fragment. Beyond that, Celeste is a random encounter you run into during the night. You need to look for her while you’re wandering around your island, so keep your eyes open.
The magic wand she gives you allows you to change into different clothing you already have preselected at your home. It makes it extremely easy to switch outfits based on the different times of day while you’re out exploring, rather than running back home.