I'm thinking that Nozomi is very slowly beginning to realize what a lot of commenters have already noticed: Nozomi is using Shino as a replacement for her dead husband, and once Shino starts her own life, Nozomi will have nothing. The fact that Nozomi doesn't have hobbies outside of work and taking care of others is very telling of how severe her codependency is.
By all means, she's a great person for taking such good care of Shino, but she is very traumatized and doesn't want to admit it, which could lead to her acting on her unconscious substitution of Shino for her husband. Which would be disastrous for Shino's grieving progress, and could potentially undo all the good Nozomi has done.