Dinah has the ability to see the likelihood of something occurring in the future which her power resolves into a percentage chance. She does this by perceiving trillions of possible universes and sorting them into groups based on a single event.
At Coil's insistence, Dinah also demonstrated the ability to pick out a single timeline and interpret it which was used to see a future where Crawler did not kill her, Coil, and the Travelers. It allowed them to find the situation where they could escape and then employ it.
She can't help but use her power if someone asks her a question, and lying about the answer messes up her power for a while after.
↑ 3.03.1“Dinah Alcott,” Weld spoke. All eyes turned to the metal-skinned boy.’’
‘‘“Beg pardon?” Coil asked.
“Thursday, April fourteenth of this year, Dinah Alcott was kidnapped from her home and has not been seen since. Dinah had missed several weeks of classes with crippling headaches in the months before her disappearance. Investigation found no clear medical causes. Police interviewed her friends. She had confided to them that she thought she could see the future, but doing so hurt her.”
--Excerpt from Plague 12.2
↑We hadn’t made the front page for any of the major papers, the first bit of good news. We made page three of the Bulletin, coming behind a one and a half page story on an Amber Alert and a General Motors advertisement. Part of the reason we hadn’t attracted all that much attention was probably because the bank was hedging about the amount taken. While we had escaped with more than forty thousand dollars, the paper was reporting losses of only twelve. All in all, the story had been more focused on the property damage, most of which was caused by Glory Girl and the Wards, and the fact that the darkness we’d used to cover our escape had stopped all traffic downtown for an hour. I’d been quietly elated by all of that. Anything that downplayed the magnitude of the crime I’d helped commit was a good point in my book.Excerpt from Shell 4.1
↑“You’d know if you watched the news,” I told Regent, “If you read the paper. I hate that I have to explain this, when I don’t even want to think about it. She’s the missing kid. Remember our bank robbery? How we were weren’t even front page news because an amber alert took priority? That was her. Dinah Alcott.”Excerpt from Buzz 7.11
↑Her voice was barely above a whisper as she stared down at the ground between us, “I’ve been waiting for this for so very long.”
It didn’t sound like an accusation. More the words of someone who had been forced to watch the clock for days, weeks, months. Anticipating a possible moment that might never come.