Emma listened carefully, not interrupting because it was clearly hard for him to get out, and she understood that. Baring everything to a complete stranger was never easy, just like telling a best friend was never easy, not this stuff, the heart wrenching, deep down, dreadful stuff. Emma couldn't blame him for wanting not to ever go through anything like that again, really. She already wanted nothing like it to happen to Jefferson again.
"Hey," laying a hand on his shoulder, Emma gave what she really hoped was a comforting squeeze, "we all do what we have to for family." Magical beacon, whatever it was, or saving your dad? Even with how little Emma knew of her own parents, how new it was to have them, she'd probably do the same a hundred times over for David.
And Stiles died for his, however he came back, he still died for him. Emma wouldn't belittle that with anything. "So, we'll just have to take what you've got here and put it to good use and figure out how to keep everyone safe. It's sort of part of the job you know, working for the Sheriff, keeping people safe from things they don't know." Emma shrugged slightly, hoping that somehow they could find a way to help.