Kathy, the seats are wide and recline quite a bit, almost like a recliner at home. They seemed to separate the seating assignments by families with babies, families with school-age children, then an "adults only" car. Hopefully your dd is old enough so you'll be placed with the adults, unless she'd rather be with younger kids also.
Many have complained here about the bathrooms being dirty, however I did not find that to be the case in late April. Nevertheless, I would heed the advice to bring anti bacterial wipes.
We packed a separate overnight bag to bring on the train, I packed clean underwear and socks for everyone, however I was the only one who wanted to change in the morning. Dh and the kids said they felt fine
Before "bedding down" (they turn the lights down around 9 p.m. IIRC) I changed into comfy flannel pants and very thick socks (no shoes) I think dh just took his shoes off, the kids were in sweats. Our car was uncrowded enough that dh and dd could each use two seats. Dd (6) made herself a little bed across the two seats. My Ds (4) stretched out on the fully reclined seat, I was concerned about him falling/rolling off, so I stayed next to him all night.
It wasn't an entirely restful night, but it was ok. Certainly better for us than continuing to drive, we had already driven 8+ hours from upstate NY.
Happy travels!
