whirled.comは安全ですか？

I agree that it's a good site which you can trust. But the users make me agree with skater4566, it's not the most appropriate site for children. The site itself is absolutely fine and most users which I have experienced are people who are either mature and some are more childish(in a good way), but there are also a lot of users(usually 12 - 15 years old, but the age can differ) that 'try to be more mature'. For example underage kids saying how smoking/using drugs/having sex is good. So yea, I wouldn't just blame 'avatars', because those are usually clean.

Excellent and fun, I don't to strongly recommend sticking to world#1 or the arcade where lots of people are. unless you want to talk with a bunch of random people (I get random invites for no reason there if I do visit it). I recommended sticking to your room(s) or your friends room.