Hi, I have a 10 day old baby who is currently sleeping swaddled, with arms out, on her back in a bassinet. The last couple of days she has begun wriggling around the bassinet and ends up on a diagonal, with her face very close to the mesh sides. I’m worried she might push her face against the side when sleeping which could be a sids risk. What should I do?

Most babies do not roll to tummy intentionally before 3 months; however some babies do roll, especially to the side, at a very early age.
Some babies also wriggle in the bassinet & end up in unusual positions as you describe.
Some babies do not respond well to wrapping/swaddling & prefer to have their arms free - which you already have done. What type of swaddle are you using?

Some babies like to touch their face or suck fingers when settling.
You could also try settling her without any swaddle.

Always place baby on the back for sleep.
I wonder if she would be more settled in a cot, with the extra space.

Red Nose does not recommend the use of sleep positioners.
Red Nose does not recommend positional products such as anti-roll devices and items that fasten a baby into a sleeping position.
Products that restrict the movement of a baby or a baby’s head should not be used.
https://rednose.org.au/article/is-it-safe-to-use-products-designed-to-keep-baby-in-a-particular-position