Layla's time alone in the Bad Future, especially the part where she breaks down in tears in front of Cyclops and asks him to kill her.
The "death" of baby Sean, not mere minutes after being born. How did he die? He was the child of a dupe, so as far as Jamie's powers were concerned, was a dupe himself. And then there's Theresa's horrified reaction.
And her reaction when Jamie returns from the future. She doesn't say anything to him, or follow up on the threats she made, she just flies away.
Theresa's parting words to Jamie after she ascended to godhood as the new Morrigan. And the fact that she comes back to restore him when he's turned into a demon.
Georgina is driven away from her Overprotective Dad who tells her he doesn't love her when she's clearly his world. The moment she's gone it's made clear that Harrison Snow blackmailed him into doing so and the alternative would have been worse somehow.
Then she learns that he wasn't her real father and she still had a mother. She gets kidnapped by her real father and then both he and her mother kill one another. This is all over the course of two days at the most.