Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
In #3, Kate is attacked by the Weeping Woman and subjected to Mind Rape. Recognizing what a threat this woman is, Kate returns to her apartment and tells Bette that their partnership is over in order to protect her. Bette presses her for a valid reason, to which Kate coldly tells her that Bette is nothing more than a glorified pageant queen who can never understand what really drives superheroes like Kate, because all she's ever lost is "a tennis match". Bette slaps Kate and tells her that she probably would've driven away her mother and sister had they not died, then calls her a control freak before leaving. When Maggie Sawyer shows up at Kate's apartment demanding to know why she was stood up, Kate starts crying in her arms.
In the second 0 issue, Kate concludes her letter to her father that she "finally became Batwoman" when she realised that her father had lied to her about Beth's death, and that she had no one left she could trust. Nonetheless, she ends her letter with "I love you, dad."
A meta-example; J.H. Williams III revealed that one of the reasons why he's quitting the series after issue 26 was because the editors forbade Kate to ever actually marry Maggie Sawyer. Which essentially means that Kate's proposal means absolutely nothing.
Following this, the inevitable happened in #34: Maggie and Kate break-up.