I think wanting this story to _suddenly_ change into a yuri trivializes the emotions of Shino and Nozomi. Anyone who has been through a big loss like theirs understands the emotional struggles of coping with the sudden hole in your life and the desire to find someone to lean on for support and comfort.
I want to see Shino and Nozomi open up to each other about their inner feelings towards each other and drop the pretense of letting the other "move on", but I don't think that it necessarily needs to go the yuri route. If it does naturally, I'd be fine with it, but I'd much rather see them become like true sisters who come to truly trust each other.