It's hard to find their positions reversed. Watching him on an ops screen is the most excruciating pain she's ever been through. Even talking him through the disastrous jazz festival was better. But watching him, knowing that he is going to make that jump even before he does, is the most terrifying thing ever, even more so that she isn't the one there to take his hand and jump. She knows that he'll play the book their way, the same way she knew how to meet up with him in Barcelona.
It kills her to know he's going to marry Parker because this kind of knowing is once in a lifetime. But if the not knowing makes him happy, she'll live with it.
And if the chapter with Auggie she so desperately wanted never gets written and instead appears her chapter serving under Lena, well she'll live with that too.