Help! Mt 5 day old newborn can roll on to her side in the bassinet? I've spent all night trying to stop her. Are swaddling and sleep suits still safe ?

Most babies do not roll intentionally before 3 months, however some babies do roll, especially to the side, at a very early age.
Often these babies do not respond well to wrapping/swaddling & prefer to have their arms free.
Wrapping her with arms out may be helpful..
You could use a muslin wrap with arms out - as per “modifying wrap - 3-6mth old” in the link below.
https://rednose.org.au/article/wrapping-babies

Always place baby on the back for sleep.

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