Hi Fiona and welcome to the Disney Parks Moms Panel.
October is my family's favourite month of the year to visit the Walt Disney World Resort - you're going to have so much fun!
You have a few options available to you as far as requesting a cot (or Pack 'n Play crib as they are called in the USA) for your youngest child goes:-
1/ Contact the company whom you booked your Disney hotel stay with and ask them to add your request to your reservation.
2/ Do you have your Walt Disney World Resort Reservation Confirmation Number? If you do and have linked your reservation on your
My Disney Experience account, you can make a note of your request during
Online Check-In.
3/ If all else fails and there isn't a cot in your Disney hotel room upon your arrival, you can simply give Housekeeping a call and they will deliver one to your room for you.
Wishing you a magical holiday filled with memories which will last a lifetime!
Emma