Samsung Galaxy S8
a doll.. 16 is still a considered a child apparently :P
but if you want to get real you can never go wrong with cash(unless she's already loaded)
If you truly want something memorable, get her an experience. No need for anyone to get vulgar with this.
Without knowing where you or she lives or what her interests are, I can't really be more specific.
For example my daughter has a really strange love for penguins. If there were any zoos/aquariums/etc nearby that I could arrange for a penguin encounter where should could encounter one on one with them, I'd jump on it. I know it's something she'd remember forever.
Trip to the spa or something. But that's if we go by standard teenage girl.
Gift card or cash
Yeah, I know she loved Disney stuff as a kid, she really likes boys now and have a crush on that dude on The Voice, which is her favorite show, she likes make up tutorials on Youtube and stuff.
But I am afraid of the makeup thing because what does that say if I get the wrong thing, plus I wouldn't want the subtle message that she isn't pretty or she needs anything like that.
Like I said nephews are easy.
Milli Vanilli, Bigger than Elvis
As others have asked, what's the amount of money you're thinking of spending?
Depending on that, you could look into:
1) Jewelry.
There's some really cool stuff out there that doesn't have to cost a fortune. Steel jewelry is pretty popular, this example would be under $150. Smaller stuff like rings etc. starts at around $30, the most expensive steel I've seen would be in the $300-400 range.
2) A day.
Think tickets for a concert, or amusement park, cinema & dinner etc. Could be the 2 of you, or for her and a friend.
Some uncle's D.
If she's not you direct relative, obviously.
I am not rich, but it's her sweet 16, so trying to make it special. If I go in on a car for something certified used and appropriate for her age is going to be about 12 thousand.
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I thought about that her and a girlfriend, but I wouldn't want to send the wrong message.
Milli Vanilli, Bigger than Elvis
Sit her down with her parents and tell/show her your favorite selfie porn site, then tell her not to be a dumbass because everyones pics eventually end up there. Then mention to her how when you were 15 and staying at your great grandparents or grand parents(who ever is now dead so she can't verify the story) that you once masturbated to a nude pic of your________ because it was in with the rest of the porn your ________ was keeping.
Then tell her that it prob wont be just her creepy uncle that accidentally jacks it to her pics but like 10 other family members and or friends and all the creepy guys at her school as well.
Keeping her from killing herself because some boy she liked posted the pics she sent him online is prob the best gift you can give her, other than a like $150k car.