Is someone at 19 to old for someone at 15?

Defaintly not, age shouldn't matter for no one.

thats only 4 years difference which is like none.

so no, they're not to old.

I disagree- 4 years is no time when some has lived for some time.

15 is a child, and 19 is someone who should be ready to live as an adult. Even if they're both still in High School, that is a big difference- lets say it was 13 and 17, not good, right, 19 and 23, ok, 18 and 22 ok, even MAYBE 17 and 21, but 15, that's a child still, no matter what anyone says.