Our 3 week old is wriggling to the bottom of the bassinet and often ends up sideways, sometimes with her face pressed into the mesh side of the bassinet. She is swaddled in a Muslim wrap and then a SwaddleMe sleep sack with arms in, is this safe? Is it ok she is moving around so much?

It is not unusual for babies to wriggle & move around their sleep environment before they are rolling.
Some babies do not respond well to wrapping & may wriggle to attempt to get out of the wrap/swaddle.

It is preferable that you use only one form of wrapping/swaddling.
Red Nose recommends using a muslin or light cotton for a wrap (or swaddle suit)

She may be wriggling a lot because she is resisting the wrapping, particularly the double wrapping.
You could try wrapping her in only one type of wrap or wrapping her arms out - as with a baby around 3 months of age.
It is important that baby’s head & face remain uncovered & as you are doing, always place baby on the back for sleep, with feet at the foot of the bassinet.

If you wrap your baby, consider baby’s stage of development. Leave arms free once the startle reflex disappears around 3 months. Most babies eventually resist being wrapped. Wrapping style should be appropriate for the baby’s developmental stage.
It is essential to discontinue wrapping as soon as baby starts showing signs that they can begin to roll, usually between 4-6 months of age but sometimes younger. Babies must not be wrapped if sharing a sleep surface with another person. Baby should not be wrapped while sleeping in a baby sleeping bag.
https://rednose.org.au/article/is-it-safe-to-wrap-swaddle-my-baby
https://rednose.org.au/article/wrapping-babies

Depending on the size of the bassinet, she may be more settled in a cot.

Red Nose does not recommend the use of sleep positioners or anything that restrains a baby in a specific position.
https://rednose.com.au/article/is-it-safe-to-use-products-designed-to-keep-baby-in-a-particular-position