Double-flanked last September. Photo: Raimonda Kulikauskiene/Getty Images Ella Emhoff, the model, designer, and stepdaughter of Vice-President Kamala Harris, and her boyfriend, GQ fashion writer Samuel Hine, can be found at pretty much every important fashion show. Most 23-year-old Parsons grads would relish this kind of excitement and its newfound freedoms, but Emhoff is under near-constant surveillance. That’s because her relationship with Hine has a third party (no, not like that). They’re striding near Emhoff outside the Courrèges show, watching her on the runway at Prabal Gurung, peering at her from mere steps away at the Met Gala. There they are, in their little ties, cropped haircuts, and close shaves: her…