E.P.
This is the age where the brain of the toddler begins to dream. They can start having "night terrors." Below is the response that I gave to another mom with a similar problem.
4-29-08
When I was pregnant with my first child (23 years ago), I was watching the Phil Donahue Show and they were discussing a new book called "The Family Bed." The author was a proponent of parents snuggling with their children during sleep. The author said, "Separate bedrooms are an artificial human invention that came along only after World War II - - as a sign of affluence. If you had money, you would show your wealth by having a house with many bedrooms." Think about it: our great-grandfathers most likely shared ONE bed with four brothers.
He went on to talk about nightmares in young children and how he believed that forcing a young child to sleep alone in a dark room just went against how young humans were MEANT to be raised. He said, "Our skin is the largest organ in the body. It is meant to be touched. If you deprive an infant from touch, it will fail to thrive."
A woman in the audience stood up and confronted this author. She said, "When my son has a nightmare, we just go into his room with a glass of water, and tell him, "Drink the water and it will wash away all the bad dreams."
The author politely listened to this woman, then he gently said to her, "Tell me, how would you feel if you went to your husband and said, 'Honey, I just really need a hug right now' and your husband said, 'Here, seetheart, have a glass of water.'?"
I decided right then and there, that I would follow the simple rule that this author proposed: KIDS ARE NEVER INVITED AND NEVER REFUSED.
All four of my children were welcome to come in and sleep in our room if they felt they needed to. If one of them came in and climbed up in-between us, their daddy wouldn't even wake up!! I would ALWAYS wake up . . . and then without a word, pull them up close, pull the covers back over us, fling an arm over them, and go right back to sleep. Sometimes, I'd wake in the morning, with one tiny leg draped across my face and another little body stretched across the foot of the bed. In their own sweet time, each child smoothly transitioned to spending all night alone in their "big kid beds". They matured naturally and could handle waking up after a dream or night terror, go to the bathroom, or just go back to sleep on all on their own. ((I discovered early on that if one of my children woke up screaming with a night terror, I could sometimes sleep-walk them to the bathroom & get them to go pee-pee, they would sleep soundly the rest of the night. Perhaps the urge to pee-pee might be a cause of night disturbances in young children just developing potty training skills.))
My daughter, was the earliest to QUIT coming in our room. She hated covers and would kick them off. She would get hot sleeping between us. So, she stopped coming in by age 2 or 2 1/2.
Waking up surrounded by kids are some of my happiest memories from that time of my life. Now, my kids are 23, 21, 18, and 11, and if you ask them about climbing into mommy and daddy's bed, they don't remember. They don't even remember going to DisneyWorld at age 5 & age 3.
Listen to me now: They will be teenagers soon enough. Teenagers squirm when you try to hug them. You're gonna' miss these days when they wanted to snuggle. : )