We didn't use a crib, Sarah slept with us in our bed with a bed rail on her side. We also rolled up a couple of large bath towels to create a bumper that was placed against the bed rail.
Flounders nursery doesn't supply anything that I know of. We supplied whatever was necessary during her stay which included diapers, wipes, toys, bottles, food etc.
They charge $6 an hour (which of course is billed to your stateroom) they give you a beeper, and you can make reservations by visting Flounders whenever you want, but if you have certain times you know you will need the nursery service it is best to book those times as soon as you can.
We only used it once for Palo's brunch. We booked the nursery shortly after getting on the ship and then went up to Palos and made those reservations too. Neither was a problem.
Jeff