From her present she can't pull from the future. She's only able to draw from the past which is era of the Fated Children; From the Fated Children's perspective Ultimecia IS the 'future' but from Ultimecia's perspective she is in the present.
She not only can't draw from future; but if she did she would effectively putting herself in the fate she's trying to avoid. So she really wouldn't want to compress that moment.
One thing to note whenever you're talking about time travel... Your perspective of time will almost constantly change.
Our present is the future to our past.




