Hi S. - the greatest SIDS danger is between 2 and 4 mos old. because they dont have good neck control and arent able to roll over yet.
Since she can roll over, sit up and has good control of her neck muscles by 7 mos, if she wants to roll over and sleep on her stomach there is going to be little you can do about it. You could spend your whole night checking on her and repositioning her - but then neither of you will be sleeping at night. Propping or back pillows are inappropriate at this age because they move around and they only become an obstacle in bed. In fact, they need to move around the crib. It helps them to develop the core strength that they need for crawling and walking.
I dont mean to contradict your Dr. Brother but these kinds of guidelines change over the years. Remember when babies were SUPPOSED to be on their stomachs? Then it was thought that spitting up was a choking hazard because babies couldnt roll over.
It's perfectly natural as a first-time mom to be constantly worried about your daughter and make sure she has healthiest environment possible. I know you want to be the best mom in the world. Guess What? You ARE the best mom in the world. Trust your instincts. Consider what others do and the prevailing advice of the day and then do what works for your daughter.
All we can do as moms is make the crib as safe a place as possible without sacrificing the quality of sleep the whole family gets. As far as removing toys, your daughter is going to quickly get to the stage where she needs a few little lovies in her crib for company. They will either entertain her in her crib until you wake up or they will help her return to sleep in the middle of the night.
The best rules of thumb are to avoid large loose blankets in bed with her or heavily padded quilts - opt for a small fleece blanky and one piece blanket pjs but avoid overheating.