Is it okay to buy my girlfriend a necklace for christmas?

i was wondering, i found a pendant that i really liked and it had my birthstone (aquamarine) in 14k white gold. yes, im aware 14k isnt so great but with the way things are going its just what i can afford atm. i bought a lenox trinket box that i want to give it to her in, but i was wondering if its okay to give her MY birthstone as a gift, like to sorta unify us in a way if that makes sense. shes done so much for me always helping me out and we really love each other. i really want her to be happy and watch her adorable smile brighten. i absolutely love to see her smile, i wouldnt trade it for the world.