I came across an interesting animation on the polaroid's i2 camera product page recently. This same technique have been used by Apple too. - Source: dev.to / about 2 months ago

Polaroids, these days, are really Impossible Project, rebranded as Polaroid. They also now have cameras that shoot different format sizes, but you are no longer limited to using vintage cameras. You can do the full-sized Polaroids, but consistency on the film batch-to-batch may not be as good as with Fujifilm. Source: almost 2 years ago

That said, if you really truly want oldtimey Polaroid feel and square prints, I would forego Instax and take a chance on the new Polaroid (fka the Impossible Project) cameras. The main issue will be the expense and consistency of the film. Fuji's much better, but the prints are tiny in comparison to full-sized Polaroids, even the square and wide formats. Source: about 2 years ago

If you care more about the quality of the instant film print, then I'd say go look at the current Polaroid cameras (rebranded Impossible Project products, really). Source: over 2 years ago

I bought it here, but I think mine was limited edition. Source: over 2 years ago

If you're looking for something more in the $100 price range, maybe consider getting a new Polaroid or a Fuji Instax printer for her smartphone. Instant film/polaroid nostalgia can be fun, and this gear is brand new, and relatively low cost. Source: over 2 years ago