The question of gift etiquette for twins is a popular one! I see the question pop up on twins/multiples forums all the time, most recently on Twins with Tots.
What should you do? Give one gift from the family? One gift to each birthday child? One gift EACH to each birthday child? One gift to only the twin your child knows? Bestow the birthday twins with 10 puppies, a swimming pool and a house with stairs? (That's what my twins want.)
Let me save you the trouble of over-thinking this. Aside from the line about the puppies, the answer is, anything goes.
Because the dynamics vary so vastly, how could there ever be a steadfast rule on birthday gift giving to twins? Sometimes the twins have one birthday party, but separate guest lists. Sometimes, especially with older boy/girl twins, they'll have separate birthday parties, with some guests invited to both events. What about when twins are invited to a twins birthday party? What then? What if boy/boy twins are invited to a boy/girl twin party and they only know the boy? What if the kids don't really know each other that well? How do you make it fair? How do you make it personal?
Ouch, my brain hurts.
See how easy it is to over-think this?
We had 16 guests come to my twin boys' joint birthday party. So that would mean 32 Lego sets for each of my boys, right? Of course not. Some kids brought a joint gift. Some brought two gifts. One brought a gift for only one of my twins, because he only knows one of my twins.
It was all over the board. Mom and dad made the most longed-for gifts happen, so any additional gift was just icing on the cake. And really what my boys wanted most of all was a chance to play with their friends. Most of the toys my boys received have more or less become "public" property anyway; they both play with them.
Remember, a gift is just that, a gift. In the realm of first world problems, it's all good. One present, two presents, whatever. Do what feels right for you and your children. Do what feels right for your budget.
The lesson here? So long as you're not gifting just one twin with 10 puppies, a swimming pool and a house with stairs, give what you like.
I'll leave you with this video, CARMICHAEL and Shane (2006). It's heavy with sarcasm and one of my favorites.