I honestly understand yellow hair POV. People often don't appreciate something they've had from the start.
In the end, she dated one girl for so long but wondered if the pastures would be greener if she followed a 'normal life' and had a family (and probably was under social pressures from ppl like her parents for this). Once she had a 'normal' family life for a while, she could finally realize that what she felt for the pink haired girl was true love and now looks back on those times...
Of course, not enjoying sex with your significant other is ALWAYS a big red flag (unless they just suck at sex lul). So she probably should have got the hint SOONER that she liked the other girl, but well, denial is a thing...RIP husband that never received wife's true affections.