Hi, and welcome.
Tracy Hogg, the Baby Whisperer didn't believe in CIO or cc since it breaks the bond of trust with your lo and promoted gentler ways of getting babies to sleep. There are other solutions xx.
Have you read any of the books? Are you familiar with the Easy concept? How does your lo fall asleep - can she fall asleep by herself?
She was quite small at birth, was she premature? She might be younger than her calendar age. Four months is a tricky age. There can be a big growth spurt, and babies change their sleeping patterns so they go more often from deep to light sleep and can start to wake more often. Also if her naps aren't great that will affect her nights as well. Can you post your typical day, like this
Wake up 7 am
Eat 7:15 am
Activity
Sleep 8:30-9:15
Etc...
Also, have a look at the FAQ sections in the easy and the sleep boards, there's tons of useful stuff there.