Trying to teach 11 mnths baby to sleep on her own in her room. i tried the cry it out but it didn't work . she keeps crying for 1 1/2 hour straight.yyy?

Stubborn: Because she is strong willed and stubborn. It sounds like she won this battle making the next attempt even more difficult. She has to sleep. She has to learn you will not give in. Let her cry all night if you must. She has to learn. You are the parent and you know what's best for her.

That's called an: "extinction burst". When you consistently ignore night-crying , it first increases in duration & intensity. Continue to ignore it & it will soon "extinguish". Go in & pick her up after 1 1/2 hrs. & you teach her to cry for that long. At a consistent bedtime,feed, brush her teeth, read, cuddle, then put her in her own bed in her own room drowsy, but awake, to learn to self-calm to sleep.