Madison Beer

Justin Bieber protege Madison Beer is understandably freaked out by the murder of Christina Grimmie, but she's not going to deny her fans face-to-face contact. Our photog got Madison, who's managed by Scooter Braun, out in WeHo Tuesday, and she made it clear ... she is deeply affected by…

Our Bieber sources say Justin has been like a big brother to Madison for 2 years, and this was meant to be nothing more than a sweet photo of 2 people who have grown close. They say Justin has helped mentor Madison in her singing career. Underage girls are all the rage -- days after 13-year-old…