I thought it might have been '2B's character model has more polygons than the N64 could draw' but as it turns out:
Courtesy of google:
Courtesy of Squenix's blog (and google):
So yes, technically speaking the N64 could have drawn 2B on screen
(with only per-vertex lighting, no normal mapping / reflection, single texture and only 50k triangles for literally everything else)
I have no idea why I bothered to fact-check this
EDIT: Though this is assuming both sources were talking in triangles. Since character models are usually made from quads (it makes things easier for digital sculpting), it's possible 2B's tricount is actually twice that, which
would put her beyond the N64's hopes and dreams.