OB Staffing

Hey all!! Would love your input on my situation. I have been out of nursing school for a little over a year. I work on a maternity unit where we do it all, L&D, PP and NB. We are a small hospital w/ about 350-400 deliveries a year. I worked as a CNA for 5 years on this unit before recieveing my Nursing degree. Last night I was asked to work w/ a new graduate that has had 8 weeks of orientation in OB, and has just come to nights, by oueselves. I was terrified. Knowing what could come in. This has happened in the past. As a new grad I was asked to be the second nurse many times and recieved very little 1-1 orientation , Maybe a month, due to staffing. I know this is unsafe and refused the assignment( before i recieved report). A wonderful dayshift nurse cam in to be there for us. But know I shouldnt be put in these situations. I have been looking for staffing guidlines and bylaws. The AAWOHN ones i can find are not current. Anyone have any links, ideas or thoughts on this matter? I love my job, and the great nurses I work with. We rarely if ever have a CNA w/us because "I was a CNA for 5 years", hear that all the time. So we do it all. I know my license is on the line, but my heart and soul are as well. Just looking for some added input. Fuel to put out this fire would be great as well. Thankyou for your input.