My 13-month-old has just started flipping herself over at night and sleeping on her tummy. Obviously she is more comfortable this way, because now she sleeps through the night for the first time ever! (Mother weeps with joy!)

However she is a very fidgety baby and so is still swaddled in a 'Swaddle Me', but with the end part cut out so her feet can stick out the end (she's too long for it otherwise).

I've just started weaning her off swaddling during day naps, which she has while breastfeeding. She used to whack me in the face if I didn't swaddle her, but recently I noticed a change in her, and I thought that developmentally she was ready for unswaddled day naps/breastfeeds - and that's working well.

So I think she'll be ready to sleep unswaddled at night soon, but in the meantime...
is it unsafe for her to be swaddled and sleeping on her tummy?
I put her to sleep on her back, but at some stage she rolls over.