While Congress retains its inherent contempt authority and may exercise it at any time, this inherent contempt process was last used by the Senate in 1934, in a Senate investigation of airlines and the U.S. Postmaster.
To make a scared cat feel more comfortable, set up a covered cave for them to retreat to. Line it with soft bedding and partially cover the entrance so that the cat will feel safely obscured inside. In the same vein of thought, you can purchase a cat tower for the cat to lie on top of.
Use a large enough box to comfortably hold the mother cat and her kittens. Stack clean towels to line it. The towels will become soiled quickly as the kittens defecate and it will be easy to remove the top towel to reveal a clean layer. The photo shows a barn cat and her kitten safe in a cardboard box.