days and nights mixed up
To be frank, that sounds like it is out of range of normal behavior for a newborn. This is, of course, assuming that you really do mean that she is up for 12 hours without resting at all. That seems extreme and it might warrant a call to the pediatrician or care provider. I've heard of babies sleeping in small chunks, but not staying awake for 12 hours at a time, which is what you describe. It sounds very difficult. Hope you find out what's going on.
Aww, hope things are getting better with you two. It is *so* hard when you are sleep deprived; I vividly remember my son who wouldn't sleep. I felt like we were up all night long. My husband (who worked full time) would get up at 4am with him and let me sleep for two hours before he left for work. Often, he drove him around because he didn't mind the car much. So, here are some practical tips that might help you: be sure that you sleep when the baby sleeps. Whatever time that is. Ignore the housework as much as you can. Ask for help from someone. Be outside as much as you can in the daylight. But sometimes, none of that works, and then only time will help. I really do hope it gets better.
Is baby in bed with you?
I don't know if this will be relevant in your baby's case but my son was overtired as a newborn. He was in an Arms Reach co-sleeper next to me at night but he really needed to be next to my body to feel right.
For weeks he would squirm and toss around all night, then when I finally kept him in bed next to my body all night, he barely moved except to nurse. The following day he napped like a newborn throughout the day and again we had more blissful sleep at night. Our lives changed from then on.
He was clearly too wired and tired to settle down and sleep, as he was overtired, sadly I think for weeks. Once he had one good night next to my body he changed noticeably.