It's true, Narcissa hadn't been spending a lot of time with her sister Bellatrix. But that wasn't unusual for them. The amount of time they spent talking would come and go with spurts depending on what was going on in each other's lives. With the recent development of a relationship between Lucius Malfoy and herself, there wasn't a lot of spare free time that wasn't taken up already. Plus, she wasn't sure if she was ready to tell people yet. She knew people saw them together which sprouted rumors and gossip about them and she loved the attention, but she had neither confirmed nor denied what was going on between Lucius and her.
She smiled as she waked into the Slyrtherin Common Room, she had just spent some time doing homework so she had the night free to see Lucius. She heard her name being called from the direction of the fireplace and recognized the voice coming from her sister instantly. She turned instantly, "Bellatrix," she cried out in kind and walked towards the sofa with grace and sat down with the manners that their mother engrained into them. She loved her sister immensely and she had missed her but there was only so much Narcissa could take of her sister's brazen personality before she was utterly drained.
"How are you doing?" she asked excited to be talking to her sister again, "I feel like it's been ages since we last had a decent conversation."