how to train my baby to sleep in the crib

So she is 7 weeks old and sleeps in her rock and play swing thing. She loves it in there that's where she has slept since the first day we brought her home. Iv seen a lot of people on here say it's dangerous to have them sleep in it for it causes flat head, neck issues and also a risk for SIDs. My baby loves being on the incline the compactness of it makes her feel snug ... the only times she will sleep in her crib is if she is completely knocked out in our arms before or if she is wrapped in a warm blanket (always wrapped loosely in this blanket so we can't use this at night because we will be sleeping and not supervising) she has slept on her back and loves to stretch her arms back sometimes too if she is in the bed with us (again this isn't an option for night time. I had not considered swaddling her as she hasn't been swaddles since the beginjng (my husband and I couldn't crack the swaddle and she would always come loose) but we got the Velcro swaddles so I will give that a go (although on a very rare occasion she does roll onto her side a little) also have a sleep sack to see if that will make her feel more cozy but jo luck this far! What to do!?!? I want her in her crib but she won't last more than 30 mins!?