Both of my girls were adopted.
Both come from different families.
But they are adamant they are twins.
They like to dress alike. They finish each other's sentences. They answer for each other. They want to be with each other all the time. The proudly introduce their sister to their friends.
One is tall.
One is short.
One is blonde.
One is dark.
One can understand all the familial relationships like aunts, cousins, grandparents.
One can memorize lyrics and do math.
One likes to be outside climbing trees.
One likes to be inside cutting out hearts.
One thrives on the energy derived from other people.
One prefers small groups of people she knows very well.
One likes her hair short.
One likes her hair long.
One prefers having her shoes on.
One prefers going barefoot when at all possible.
Someday, my guess is, they will be happy being different. They might be relieved to have some time independent from each other. They might choose different friends or activities.
But for now, they are twins. So close in age and in situation, they are comforted by each other's presence. They are entwined in shared histories. They have years of togetherness that draws them together. And they revel in each other's company.
My goal for them is that they become and stay best friends. Because there is no other relationship like the one you have with your sister.
I think they're on their way.