Co-sleeping toddler

My girl is almos 3 years old and now we have an 8 week baby, baby sleeps in a crib in our room and toddler has slept with us since she was 1 month old... She has her own nice and cozy room but she wont sleep there! It's hard for me too but it's time for her to move to her own room, right now its almost 1 a.m. and Im lying here with her in her bed, she just fell asleep and I'm afraid when I get up she is gonna wake up or even worse she is gonna wake in the middle of the night and get scared! This will be my first try and I am almost as scared as she is! Does anybody have any advice? I will much appreciate it, thank you!