[QUOTE=Shodan]
We celebrate the anniversary of their arrival as a sort of second birthday. Have a cake, show the video of them arriving, make a celebration of it. That way, they just always knew they were adopted.
But congratulations and best wishes - in advance.
Regards,
Shodan
[/QUOTE]
Our kids are both adopted from South Korea. ( son is 16, daughter is 14 3/4 ). We call it their Arrival Day. Funny I’m reading this thread right now. An hour ago, I drove daughter and her gal pal C. to the movies. C. has two cousins who are Korean adoptees. She said their parents call it their " Gotcha Day". I like that too ! 
With interracial adoptions, it’s obvious. I agree strongly with what Omega Glory has said. If it is always a part of what makes your family your family, then there will be no shock, no huge moment of revelation. He/she is adopted, it has always been a fact in the family and a gateway to talking about other adopted folks you may know. One bio kid and one adopted kid? Great- that gets talked about too.
We always joke about how we delivered our children the easy way- at the airport. ( more than a bit of covering up for 4 1/2 years of agonizing and psychologically destructive infertility.).
My mother recently shared a story. Basically, her friend had been married twice, but the first was very young and short-lived. It produced a girl, who was whisked away along her mom in the middle of the night ( literally ) to escape a violently dangerous husband.
She was never told. As far as she knows, my Mom’s friend’s second husband IS her father. Now, these people are in their 70’s, and the daughter is around 45. I mean, my god. At this point it would rend the family into pieces. I feel like there is no right time now, to tell her. ( see what Interface2x just said below ).
That is a shame. If only they’d found ways to let her know the story ( appropriately sanitized for a small child ). Her father, the only one she’s ever known, lives for her happiness and has never considered her anything BUT his daughter, biology notwithstanding.
Cartooniverse