Narcissa's feelings regarding Andromeda had been conflicted for a long time when they were younger. On the one hand, she could not approve of her sister's actions, nor did she disapprove of the way their parents had reacted. But it was her sister. She would have loved her sister even if she hadn't liked her, because that was how families worked, in Narcissa's mind. However, for years, she pretended that Andromeda was dead to her, simply because it was either that or get painted with the same brush. By that time, she was set on making a name for herself (though not as a Black, as a Malfoy), and she wanted no black marks on it.
Now that they were friendly again... it was lovely, but it was dangerous, too. Narcissa was glad to be able to think that she had three sisters, having an extensive family circle with herself at the center. But there were certain precautions that had to be taken if she wanted to have any family reunions.
Stonehenge, she hoped would be somewhat empty, at least of the people that they normally associated with. This time of year, people were deep in their studies or their jobs, and having winter and holiday parties in their free time. No one wanted to come to Stonehenge when it was so cold, although as Narcissa approached, she found herself thinking that the dark stones were almost more striking against the cold, white and grey tones of everything else.
She knew Andromeda at a glance, not because she had seen her recently, but because of her stance. Her head held down and cloak obscuring her face was almost more indicative of her identity than her features would have been, although only because Narcissa was looking for her.
Approaching the site, she removed her hood and gazed almost casually at the stones, letting her blonde hair give her away. She didn't want to make their meeting look obvious, after all.