I think it can all be very simply explained: it takes someone who is sure and confident of his/her own talent and success to recognize another such talent, no matter if younger in age or in years in the business.
Lea Salonga, a Filipino of international fame especially in Broadway, is one example. I've tried to transcribe what she said about Charice in her interview at Broadway.com:
Show People with Paul Wontorek, Editor-in-Chief
(Lea talking about Charice starts at 12:52 of the full video linked above)
Paul Wontorek: I want to ask you sort of a random question. What do you think of Charice?
Lea Salonga: She's wonderful.
Paul: She's from the Philippines.
Lea: She's from the Philippines. Yes, we proudly own her. We will proudly own her and, you know, obviously none of us can take any credit for her talent and for her ability and for her skill. That's really just hers, and her mom's, and her family's, and everybody that's trained her and taught her to do what she does. But you have an entire country who is just proud of this, of this young woman. I mean she's been on Glee. I mean she's doing concerts, she's toured the country with David Foster. I mean she's got the whole world open to her. It's pretty damn awesome.
Paul: It reminds me when you were that age... So have you met her?
Lea: Oh yeah, and we've actually sang together a couple of times. She's just amazing. Amazing singer and amazing musicality, so... she has no problems getting to where she wants to go. She'll do just fine.
Paul: So maybe you should like play her mom on Glee or something.
Lea: Well that's really up to the people at Glee.
What's transcribed above is also included in another video compilation of Lea Salonga interviews wherein Lea praises Charice. Thanks to jamie34peters for uploading it on YouTube: