The irony of misogyny
Not only are women tasked with the unimaginable tasks of child-rearing and child-birth, Brittain's dad somehow believes that just because she is a woman she is unable or biologically unequipped to live in reality. Ironically, her father's opinion is literally that women are weak and inferior, but it wasn't because she was a woman that life was brutal and painful; it was because of people who made their political interests into wars. Misogyny did not protect her whatsoever.
The irony of WWI
When she volunteered to be a nurse, she probably felt nervous, but in light of what the role meant in the past, she might have expected to see an occasionally gory injury, but mostly, maybe she'd just patch wounds or something. The irony of WWI was that alongside everyone else, she was truly blindsided by the horrors of those battles and the new equipment of war. The horror was unendurable and unfathomable.
The irony of PTSD
There is an ironic replacement of the old Vera Brittain with the new one. The old Vera Brittain felt that her relationship to the past was unnecessarily painful, and she went to school largely to discover her own potential and to become powerful. Compared to the reality of war, these problems are given over to more immediate issues like overcoming panic attacks. The irony is that although she was already unhappy, her life because way more arduous and painful before it got better.
The irony of G
Although perhaps the reader might cheer when they read that G accepts Brittain and her feminist insights, but to Vera herself, she admits it was ironic, because she knew she loved him, but for some reason she had to muster the courage to confront him about her opinions and past. This irony is admittedly a window into Vera's social paranoia, but also it is a demonstration of her autonomy and independence.
The irony of social situations
One last irony that the reader should not underestimate is that because of the love she had for her friends who died, Vera's body is scared of connecting, because the mourning and agony of their horrifying deaths was so frightening to her that although she is clearly an out-going person, paranoia about panic attacks and PTSD episodes brings her into a new approach of social situations. She must learn to connect with people anyway, despite the risk of pain, but in a new and wise manner.
