Ginny and Hermione's relationship.
Hermione may have confided in Ginny about her true feelings for Harry.
We know how Hermione advised Ginny to grow out of her Harry crush by dating other people. Perhaps Hermione did tell Ginny she sees Harry as a brother and nothing more.
We never see Ginny being jealous of Harry and Hermione's relationship the way she gets with Cho. Perhaps she trusts Hermione enough not to whisk Harry away.
Do you think Ginny would be secure about the bond her sister-in-law and husband share as Ministry workers?
I'm interested to see how the Hermione/Ginny's friendship evolved as adults.