Thane and Samara should have interacted more often in ME2 and ME3, at LEAST as friends, if not more, especially if Shepard didn't pursue either.
No way Thane wouldn't see Samara as a Siha, and Samara finding comfort in someone experiencing similar end of life aging, and child raring regrets.
The two companions soaked in their comfortable silence. Eyes closed until Samara caught a hitch in Thane's breathing. It brought her back to the ship, on the hard ground, under the infinite void and uncountable stars. A well-known bittersweet feeling invaded her heart and clouded her thoughts. She knew that soon, she would no longer have this shared tranquility.
"I never thought I would find such familiar company in the vastness of space. My code never permits time for such peace...thank you." Her dark blue lips push for a smile as her piercing eyes gleam toward him with serendipitous joy.
"I've wallowed in my battle sleep for ten years, Samara... Siha...it has left me cold and empty. I had considered myself already dead. But when I hear the sound of your heart, I am reminded that my own still beats... I believe this thanks is mine." He holds her stare, studying the moment as if to capture it forever. He gives a smile back to her and moves his hand to hold hers, covering it as an act of protection from the sorrow that is soon to befall them. They both returned to their quiet meditation, hand in hand.
Friendship? Love? The two did not care to label this feeling. They had no time to worry about trivial issues, not when they could bask in the warmth of each other, for soon will come, but it wasn't here today.
Samara would visit him in the hospital (this is where Shepard would meet them both for the first time in ME3) and even rushes to the hospital at his request as he dies to Kai-Lang. You will see her at the temple later after saving her child, and she will lemant not killing Kai-lang for Thane, whispers that the sea calls to her, promising respite from the terrible demand of her code. Her hand trembles ever so slightly as she brings death near her temple, finger clinging to the only solution she can think of... but you save her from herself. Your friend almost breaks down in tears. As you explain, she doesn't have to, Thane and her children wouldn't want her to do this either. Her daughter steps forward to express her intentions of staying, and Samara is embraced by her offspring. She prays to Shepard for shaking her beliefs ever so slightly and to Thane for offering a place of peace as she silencely recalls his prayer for her.
Liara finds emails between the two, a few letters, speaking about their children, the trip on earth where she "happened" to have work. A final letter Thane sent to Samara (it is similar to the one Shepard gets) and the one she tries to send back.
"No matter how dearly I held my code, and think of its importance. I dream of my daughters, of you, and my chest hurts with a wish that I had held you all much closer than that..."
