Hmm. You're right about the talking, he's doing fine. Boys especially often don't talk much until well past their second birthday.
About the sleep, she may have a point. It doesn't matter so much when he sleeps, true, but it's probably best if he sleeps on a regular schedule. And 10 hours a night might not be enough, unless he naps a lot.
Still, you are the parent. It's your decision, not hers.