MM born in the 90s are very young. Most girls of this age like personalized things. Your gift must be original. Let me give you some ideas.
1. It is a good choice to DIY a more important sterling silver handmade necklace with your girlfriend's constellation. Such a necklace is not only easy to match with clothes, but also makes your girlfriend's princess temperament immediately appear when she wears it!
2. It is also a good idea to give your girlfriend a handmade sun jar with twelve constellations. Such a gift can be placed in the house as a decoration during the day. After it collects sunlight during the day, it will emit warm light at night and can be used as a night light.
Customize a long-sleeved T-shirt for your girlfriend with her constellation. It is best to make the constellation into a cute cartoon shape. Your girlfriend will definitely wear it as soon as she receives such a gift.