Lavender was in shambles, and, let's face it. Worry was not becoming on such a pretty face as her own. In between forcing herself to stay awake (she wasn't at all convinced that Fenrir wouldn't come breaking down her door), and now having to be concerned about the current state of her best friends, well, it had led to several panic attacks over the course of the past day or two.
And when Lavender had panic attacks? Hell hath no fury.
The degree to which people were trying to pass off their absence as 'nothing,' was incredibly irritating. Wasn't the motto better safe than sorry? They didn't know her boys like she did. In some situations, sure, maybe they would go a few days, or even a week without talking. But after the given pre-existing circumstances? No. They wouldn't. They wouldn't ever.
When Luna had agreed to meet her so that they could check up on their houses, she was thrilled. They'd get to the bottom of this. Hopefully.
Having been cooped up like a frightened mouse in her house for the past few days, Lavender had taken a longer amount of time than usual to get ready. By the time Luna knocked on the door, she grabbed her wand, and darted down the steps to answer.
"It's fine," she quickly babbled, and tugged the door closed behind her. "Seamus. Let's go to Seamus' first." Maybe she'd feel bad about side-waying Dean later on, but now? Her main concern was Seamus.
She's justify it with the fact that he was the one who had the bad omen over his head.