Her memory might not be like the drell's, but Shepard will never forget Thane Krios.
She doesn't try to forget him, doesn't try to move on, because he deserves better than that.
Had he been the one to outlive her, he would have spent every second remembering something about her.
Like the way she talks, and how her hands feel when she holds his; the way she moves, and the feeling of her bare skin against his when they move together. He would remember the sounds she makes; the ones when she's mad, the ones when she dares to open up and let him see her sadness, the small sounds she makes when she sleeps, and the ones she makes when she's with him: the sounds she only ever made with him. Thane would remember the scent of her skin, be it clean from a shower, or sweaty and bloody and dirty from a mission.
She knows his memory is… was like that because he's a drell. But that's not the entire reason. He remembered everything because he let her close, because she felt safe enough with him to open up and let him in. Because she loved him and became his Siha.
Shepard was not his first Siha, because the first one had defied him, hindered him in killing a target, and gave him his legacy.
She cares about Kolyat, and she is glad she got to know the son of the only person she's ever loved. And she feels sorry for him, because he's lost both his parents.
She hates The Illusive Man and Cerberus for what they did, but she knows she owes them for saving her, for bringing her back. Mostly, she owes them for bringing Thane into her life.
Shepard hates it, but she told Thane one night, as he lay beside her on the bed. She told him she hates it, but that she would gladly have it happen all over again, she said, because she loves him and even though she knows he'll die one day, she wouldn't have done anything any different.
She also knows she might be the one to die one day, maybe even before him.
So she makes sure to thank him before every mission, just in case she doesn't come back this time.
Knowing about his disease didn't make it any easier, but at least she was able to say goodbye.
And she knew he loved her, would always love her – even now, as he was on the other side of the sea – but that he chose to use his last breath on a prayer for her was something she had never expected.
Thane is the only thing on her mind when they take the last stand against the Reapers.
And they won. Somehow they managed to win.
Shepard didn't expect it, hadn't expected to survive.
She had been prepared to die, to finally be done with what has come to seem an eternal battle.
But they weren't safe.
Something shot them down, and Joker barely managed to land the ship.
Being stranded at an unknown planet, especially so soon after a victory was not something they were prepared for; it was something completely unwanted.
But they did what they would, and prepared for a long wait.
She walked into the sea on a Wednesday, nothing to weigh her down except her heart.
Her body covered in bruises and scars, testament to the torture she had endured when fighting the Reapers and the Illusive Man.
Naked, she stood on the cliffs high above the water.
She wanted to die like she had lived; like a bird soaring high above.
But her wings had been clipped and cut.
She pummelled down, down, down, and hit the water so hard every bone that had not yet been broken, shattered into a thousand pieces.
It didn't hurt, for some reason, not like she expected it to.
How fitting, that the only place she had ever called home - and meant it when she did - would fall down in this place.
She knew better than to call it luck or fate, but she was past caring.
Maybe it was luck after all, that her home would break apart and bring her to a sea.
She had smiled as she fell, and the smile was still on her lips as she bled out and breathed in water.
At last she would find her way to the other side of the sea and be with her love again.