Thanks!
I persisted for aout 4 days - every nap there was at least 15-20 mins of tears and during the night she was waking more oftern SO I have gone back to wrapping her. She still rolls but I think she is fairly safe as she is in a sleep suit with little arms so can still prop her head up - and if not she is a loud crier!
I might give it another go when she is 7 months old but for now I will work on getting more sleep in the night.

Thanks!