If she just ate it this morning she may not pass it until later today or tomorrow. It all depends on if it becomes lodged, held up & how fast her intestinal tract is moving.
And if it does become lodged she may not start to show ill symptoms until a day or two or three, it all depends on how fast it is moving in her intestinal tract (if it can even leave the stomach) and how bad it becomes lodged. She can always have a partial blockage which won't show as many symptoms as a full blockage. Symptoms from a partial blockage may take longer to show than a full blockage, anywhere from today to a couple/few weeks from now even a year or two down the road. It all depends on how much of the intestine it is blocking.

If she ate half of your shirt I'm sure you'll be able to see pices here & there in here feces. If she happened to swallow the half of shirt whole there is a greater chance at her having a blockage as it is a larger piece.

Just desect the feces. I hope Whiskey passes it.