Help adopting my daughters in QLD. My step daughters, but my daughters 🩷

Has anyone else been in this situation, a wonderful one, where you marry an amazing man or woman with amazing children? Those amazing children call you Mum/Dad literally from the 1st day you met, they couldn’t wait till you actually got married so they could ‘officially‘ call you Mum/Dad (in their little heads only, because, they did already but the wedding just made it official for them). The other biological parent has been absent almost their entire lives, since they were babies. (My husband did a phenomenal job raising two little bubs on his own btw)

There’s actually very few that don’t even know I’m not their biological Mum, and those that do know, treat them as if they were. Its crazy because I sign school forms, take them to the doctor.. know every inch of their little lives.. friends, foods, fears, loves, heartbreaks, hates everything a loving mum knows.. everything, they are my daughters!! We don’t have a lot but my husband and I make sure my children have the best life possible and they are happy, it’s been almost 4 years (they are now 8 &9).

My question is, is it possible for me to adopt our girls without bringing the biological mother into the picture? She really was not a good person and the thought of bringing that element into their stable lives scares us. Has anyone been here?? does anyone have advice?