She had been standing in front of Number 12 Grimmauld Place for about five minutes now. Logically, she knew Sirius probably felt the wards activate, and there were security measures around the property that alerted the inhabitants that she was outside, but she couldn’t bring herself to knock on the door. The entire Weasley clan was at St. Mungo’s spending time with Mr. Weasley after he was attacked in the Department of Mysteries, and she wanted to stay close to her adoptive family, so she made the decision to spend Christmas at Grimmauld. Knowing who else was living at no. 12 didn't hurt either.