"He was my favourite cousin when I was younger. It seemed fitting," she admitted before frowning just slightly. "I... you can't mention Sirius here though. Just-- for Remus' sake. They were close and he's not here now, so..." Tonks trailed off. It wasn't the complete truth, of course, but she didn't want to tell Bella that in about fifteen or so years she'd be the one to kill him and that's why Remus would be looking to hex her on site.
Tonks knew she was going to have to deal with that later, but she did intend to keep her promise to Bella. Neither she or Remus was going to hurt her. She was just seventeen and not guilty of any of what she had been in their time, and stuck here, it was likely she wouldn't be. Not if Tonks had her way.
"I'll find some of them in a bit," she said. "I'll show you the rest of the apartment first, and your room. I've magically expanded the place a bit, so we've a lot of extra room space, even with the nursery."