1. Eowyn and Faramir...Will and Lyra...Rose and the Ninth Doctor
2. Sam Gamgee...Neville Longbottom...E.T.
After writing all that, it occurs to me that Kyo/Tohru might be a better third example for #1. But I'll leave it as is, and still leave open the invitation to provide other, possibly better, examples. I'm still not fully satisfied with that anyway, as I'd really prefer a third example that is also from a prose novel.