Need some information on Missouri law

1 year ago I adopted my step daughter, which was placed into our home by DFS almost 4 years ago. My step daughters biological mother gave consent to terminate parental rights, and our attorney set forth a plan for adoption. The question is, is it required for someone to adopt a child in Missouri after TPR? My mother-in-law is up in arms that I insisted on this as a form of controlling my husband and it was unfair to the child, even though she has referred to me as the childs Mother since DFS placed her with us. I would have adopted the child regardless of the state requiring it or not, but would just like to know so that I can prove I did not have some kind of "conspiracy" in mind when I did it. Thank you in advance