I think younger people are still a bit too immature to be taught or talked to about gay or lesbian people.
I really don't think so. I mean I don't think you need to sit down with a child and talk details or anything. But I see nothing wrong with letting a child know that sometimes two women can fall in love or two men.

This past weekend my cousin went with me to gay pride and brought her daughter along. Her daughter is 5, she doesn't fully understand everything. But she is aware that a couple isn't always just a man and a woman.