Thank you for your patience as I researched this.
I could find no statutory or case authority which would allow 2 unmarried people to adopt a child. It is most likely because it can create too many problems- for example, who would have legal custody, visitation etc. Typically that requires either a biological or marital relationship.
However, AZ does have a streamlined process for step parent adoption, so once the marriage is effectuated, that can be the avenue by which to proceed.
Here is the statute that governs step parent adoption:
This site is currently not working - but it provides useful information on step parent adoption if you want to try back in a few hours.
Also please see:
Thank you for using Just Answer.
I hope the information I provided is useful. If you need further clarification please post here and I will reply as soon as I see it; otherwise, Kindly
This does Not result in additional charges to the customer and allows the site to credit me for assisting you today.
Thank you and take care!