Wow 
That's some haul, there...
As PPs have said, it so depends on what's regarded as "the norm" to them. And maybe 4 DGParents etc. have chipped in to that little stash, on the quiet?
Personally, I'm saddened by how much social media makes our teens overshare, but it has become second nature for a lot.
In this girl's case, it depends majorly, too, as to tone of Insta post:
if birthday girl is generally a kind, supportive, non-judgemental etc. friend to your DD and peers, and just happens to come from a wealthy background, might the photo be in a "Bloody Hell! Look what my crazy parents got me! Am in total shock: never expected that! Can't wait to enjoy it with you all, though, eh?!", appreciative type of manner?
But, yes, if meant with sneering, "you lot are never going to come close to this on your 18th, let alone 17th birthday, you losers" attitude, then I imagine your DD wouldn't be that close a friend anyway?
Comes down to parental attitude and a varied mix of friends from all backgrounds, I guess...but hope her Mum's not a MNer, for your sake!
Slightly off at a tangent, but relevant:
One particular family local to us is in the old money, titled, mega-wealthy 10%, and yet their 4 kids couldn't be more down-to-earth and made aware of what a privileged life they lead.
Genuinely lovely boys, who automatically share, muck in with everyone, the eldest have p-t jobs, the littlest one always popular down at our local playground for his nice nature, not the toys etc.
Their parents do a bloody good job at ensuring they don't live in a bubble, and end up clueless about what real life's like for most.