How much should parent spend on adult child gifts?

Nothing! An adult child is an adult and just a card should be fine. No matter how old your child is, if you feel you want to give them a gift then do so. Often when people are in conversation they don't pick up on things people say they may need. It could be something very inexpensive. If you have good financial means then there would be no problem, but ANY GIFT should be appreciated. You could send flowers, give gift certificates to a clothing store or a beauty salon for a daughter, or, tickets to a sports event for your son. It's all up to you. If you choose to not give gifts any longer then make sure you communicate this fact to your children. Most of my girlfriends are all in their 60's (most with grandchildren) and they still give their children Birthday and Christmas gifts. Hint: For daughters costume jewelry such as a pendant on a chain, a ring or bracelet in COSTUME JEWELRY (generally very inexpensive, but well made) is a good gift. If your son loves movies, then get him a few tickets to a movie theater. If there is a concert for a certain band or a theatrical event coming up that your daughter or son may want to see get them tickets.