Funny thing about the Internet, you never really know if you are talking to a crook, a short order cook, a BATFE Agent or maybe even a Federal Judge!
But Yeah, I'm Sure if you went and paid a lawyer several hundred dollars, waited weeks for the researchers, He would tell you the same thing.
The technicality of it is, you must be 21 from a Licensed Dealer.

you can give your 18 year old a handgun as a gift
you may buy one in a private party sale at 18 years of age (at sellers discretion)
You may also allow your minor child to be in legal possession of a handgun while under your direct supervision as provided by the law (which gets a bit stickier)