A few weeks had passed since they magically dropped into these new lives yet into their old bodies. They had chats and explanations with their parents, they both met Kristoff and tried to hang out with him as slowly and naturally as possible. Elsa helped her father during royal councils, having good experience, Anna helped her mother on hiring the new staff, knowing in advance who are the best candidates.
They also spent way much time together, which their parents still found weird after seeing them - and asking them to be - separated for so many years.
That evening, they were once again spending some time together after a long day, both laying down on the big couch of the 2nd floor's living room. They were not saying a word, just silently enjoying the presence of the other. Anna had her head on her sister's lap, reading a book, while Elsa, wearing an absent smile, was playing with Anna's hair. It had been a long day, quite exhausting, especially with the fact it ended with a run of the two sisters in the corridors. The elder had once again taunted the younger about their height difference. In the future - which was their present - Elsa was slightly taller than Anna, but it was barely perceptible when one or the other was wearing flat shoes or heels. However, now that they travelled through time, they noticed that Elsa kept the same height, but that Anna was much shorter. She hadn't finished growing. They had a fight in the late afternoon when Elsa took advantage of that to put the last jar of cookies on the top shelf of the kitchen. She also created ice chains around it, as a joke, with a lock on which was written 'Not For The Tiny One'. And yes, it resulted in a pillow fight in the corridors.
Struck by this memory, Elsa suddenly stiffened. As she was stroking Anna's hair, the youngest sister felt her stop.
"What is it?" asked Anna, putting her book down and lifting her eyes to Elsa.
"...Nothing" lied the blonde.
Anna completely changed her position for a sit, closing the book and staring at her.
"What are you thinking about?"
Elsa took a while to express herself, but actually her gaze betrayed her. She was staring at Anna's pigtails.
"Is there something wrong with--"
Anna realized what it was all about. In her question, she had lifted one of her braids, and she saw in her hand...
"You're looking at the white strike, isn't it?"
Elsa simply nodded, and gulped.
"I... It's... Yeah, that's obvious you have it again. I mean... That you have it now. That you still have it" she stammered.
Anna took her hand, and they exchanged the usual 'It's alright' gaze that was worth a thousand words. Elsa sighed.
"Can I ask you something?"
"Do you..." Elsa coughed, trying to hide her emotion. "Do you want me to take it away? To erase it?"
Anna knew this question would come. Obviously. Every morning she woke up since they have this new life, she stared at it in the mirror, fully aware that Elsa had the key to make it vanish. Love. Confidence. Self trust. Everything that her sacrifice on the fjord made her realize. An act of true love, in every way.
"As you want", smiled Anna. "Only if it makes you comfortable."
Elsa cringed, but part of it was a smile. "Seeing you with it makes me uncomfortable."
Anna chuckled. "Okay then. Do it. Do you know what to do? How to proceed?"
She barely had time to sit still on the couch, that Elsa already lifted her left hand and made a soft motion of the wrist. Something tickled on Anna's head and instantly, the white hair seem to melt away.
"Here" smiled Elsa, with as much tenderness than relief. "It's way better."
Anna looked at her hair. Her smile matched her sister's.
"I love how easy it is for you now."
They resumed their position and continued their routine as the sun went down on Arendelle.