I can understand how concerned you must feel, especially since EVERYWHERE you look and read, there's some expert telling us to let our babies cry it out, they must have a self soother, and blah blah blah. As a first time mom, I ran myself in circles trying to get my son on schedule and get him into self soothing. You know what happened? I said screw the experts!
I gave my son a bottle before naps and bed. I knew I could be getting myself into a lot of trouble, but it turned out to be no trouble at all. My son weaned himself off his bottles when he was ready, and learned to fall asleep when he was tired. He sits with my boyfriend and I, and falls asleep on one of us. And then we put him in his crib. He is a cuddler when he's tired. I don't care that he falls asleep on us. It's what works for us.
So do what works for you. She'll figure out some calming skills on her own. Babies know these things, and they eventually figure it all out. If you're still worried, maybe try pumping and introduce her to bottles. So that way she can get used to other people putting her down.
Trust your instincts. My son slept in a car seat for naps at his babysitters (it's the only way she could get him to sleep) until he was 10 months old. You gotta do what you gotta do to keep your sanity and keep your baby happy and well rested. My son slept on his stomach since he was a week old. It's what made him comfortable and helped with his gassiness.
Just go with the flow and follow your baby's cues. She'll let you know. Good luck!