She's too young for cry it out and WAY too young to be on a strict schedule. She should still be fed on demand.
I hate that so many so called experts make moms feel awful if their babies aren't sleep through the night by the time their 2 months old. In my experience, it's simply not true. Yes, there are the babies that sleep all night long, but there are also those that don't.
The only way your baby had to tell you something is wrong is by crying. I look at it like this, if I'm thirsty in the middle of the night, I get a drink. If I'm starving I get a snack. If my preschooler woke me up at 3 am and said "Mommy I peed the bed." or "Mommy I'm thirsty." I would get out of bed and take care of it. I think the same principal needs to be applied to little ones.
I totally understand that you work and don't want to be up all night long, but are you really going to be sleeping if the baby's crying? Wouldn't it be better and easier if you just fed her when she woke up? Then everyone can go right back to sleep.
That's just my two cents. :)
I wasn't very familiar with the method you were talking about, so I looked it up. I found this quote on ehow.com
"Babies who are younger than 6 months old should not be allowed to cry it out using the extinction method. Young babies don't understand the concept that you're coming back for them, so their needs must be met as soon as possible."