Transitioning baby into a grow bag

Hi ladies,
I just wanted to seek some advice on how to transition my little girl into a grow bag with her arms out when she sleeps.
She's currently swaddled with her arms by her side as that's the only way she'll sleep.
She's just started rolling and wakes herself up when she rolls onto her tummy and can't roll back onto her back. We've tried swaddling with either one arm out or both arms out but she just keeps knocking her dummy out and wakes up.
I'm just abit lost for ideas as we never had this problem with our son. He slept in those sleeping bags with his arms up above his head so transitioning him to sleep with his arms out was no problem. Our little miss hates the sleeping bags with her arms up above her head.
Sorry this was a tad long - but thank you in advance for your suggestions. ?