She didn't have a lot of experience with death. They'd left Budapest when she was only five and her memories of her father and the war he'd been fighting were vague. By the time she was old enough to have more vivid memories, her mother had become that strong-willed, spine of steel woman that Florence knew and, despite their differences, loved. So she really didn't know how to deal with John's loss.
No, she'd never gotten on with Sherlock. She'd never understand how John could be so loyally devoted to a man who didn't seem to care about much of anything ninety-five percent of the time. Even Freddie showed more emotion than Sherlock Holmes did. But she knew John had loved the man dearly, and she refused to judge that. Everyone had questionable choices in their lives. Sherlock was John's.
She couldn't take his pain away. That was one thing she knew. She could only offer him support and understanding and love while they waited for the hurt to fade. And at least he hadn't pointed a gun at her, which was a small thing to ask at that point. So at first, she'd only just sat there near him. But there was something oddly horrifying about watching one of your closest friends cling to the corpse of his best friend. And the fact that Sherlock was, in fact, lying there dead, was in itself difficult to handle. Instead, she'd started tidying up the flat, occasionally stopping when she saw him tense at an object being moved. He wasn't ready for anything of Sherlock's to go, and that was more than understandable. It would probably be a while before he could let that happen. So she worked around the detective's belongings.
But when she heard the first gut-wrenching sob, she gave up all pretenses of being there for any reason other than being there for her best friend. Florence made her way to his side and knelt next to him. Words weren't even possible. Nothing she could say would help him. Not just then. So instead she rested one hand at the back of his neck and rubbed soothingly, letting him cry. If this was mothering, then be damned. John could use a bit of extra care just then.