Just a weapon swap - the model itself is a 1/35 female us navy 54mm model, which can be dug up on ebay using those search terms or similar ones.
I swapped out the right hand for a cadian laspistol, and squeezes a space marine knife from a 2nd edition sprue into her left hand, and then decorated the base a tiny bit.
The rest is just painting.
This is a case of me seeing the sculpt and liking it too much to alter it much at all.
The only proper 40k callout is her laspistol, and the Inquisition symbol on her right arm.