Can I add my partner to my subclass 190 visa application after lodging it?

I lodged my application in March 2020, claiming single points (10). It has been almost a year and I’m still waiting for my grant. In the meantime, my gf and I moved in with each other and are now in a defacto relationship. My partner has a positive skills assessment for Accounting and has superior English. If I add her to my application, my total points would remain the same. Only my relationship status would change from single to defacto. Is it possible to add her to my application while it is still being processed without risking refusal?

Since you claimed single points for your EOI and lodged your application. Post lodging, the department verifies your claim which you have submitted. Any discrepancies from what you claimed to what you are presenting will be taken under strict review. And chances of being refused are very high. It would be better that you apply for partner visa after being granted your 190, that’s the safest option you have now.