Your baby is totally normal! What she's doing doesn't fall under the definition of a "sleep problem" at all, even though it's tough on you. The surveys about sleep at http://www.kellymom.com say that only about 50% of normal infants at one year sleep through.
Our culture puts painfully difficult, unrealistic expectations on us!
http://www.kellymom.com/parenting/sleep/sleep.html
Research shows that the central nervous system naturally matures enough for baby to get to sleep and back to sleep after waking, without a parent's help, at the age of around two years. See "The Sleep Patterns of Normal Children", Armstrong KL, Quinn RA & Dadds MR. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retriev...
Medical Journal of Australia 1994 Aug 1;161(3):202-6.
“It is not until after 24 months that regular night waking (requiring attention) becomes much less common.”
Why on earth do they wake up so much, why doesn't the nervous system mature earlier so they (and we) can get some decent sleep? James McKenna at the University of Notre Dame's Mother-Baby Behavioral Sleep Laboratory has been studying infant sleep for many years.http://www.nd.edu/~jmckenn1/lab/ He has found that it is completely normal for babies to wake easily and frequently. It is probably a protective mechanism designed to help the baby wake and alert for help for the simple reason that for the tiniest things, a baby cannot help himself and can get into a bad situation quickly. If they were deep, long sleepers, they'd be unable to rouse and alert for help.
His reasearch has found that sleeping near your baby can help the little one regulate their breathing, temperature and sleep - all the systems that are still maturing seem to respond to close contact with mom during the night by becoming more stable. So babies are hard-wired, in a way, to request mom's close and frequent contact at night, as a deeply instinctive mechanism that developed to help increase a newborn's chances of survival.
It is appropriate to respond to her cries for you when she needs help. She cannot tell you any other way if she is hungry, cold, has a cramp, a tummy ache, growing pains etc. If you do use CIO, none of those things will go away. She will just have learned to not bother asking for help because it won't come. Katherine Dettwyler, an anthropologist who studies infants, has a great article that explains some of the needs of human babies. http://www.kathydettwyler.org/detsleepthrough.html
As if that's not enough, the Australian Association for Infant Mental Health has a position paper on the CIO method that explains exactly why it isn't good for babies:
http://www.aaimhi.org/documents/position%20papers/control...
another helpful article about sleeping through the night:
http://www.drjen4kids.com/soap%20box/sleep%20stuff.htm
and for what it's worth, she may truly be hungry. I wake hungry in the night all the time, so I know it is even more likely for a baby.