IMO AJ was kinda stuck with the whole last name thing. Originally, I think legally she had last name of bio Dad (Langer?)and it made complete sense to go by Hoffer when Mom was married to Zach and everyone in house was happily a Hoffer (really wish it would have stayed that way b/c I wouldn't be posting this then and AJ would still be alive). Then.... when Mom marries WH and becomes Hadsell, really, if you think about it, becoming Hadsell is the only thing that makes sense. She is not legally a Hoffer and since Mom not a Hoffer anymore, continuing to go by Zach's last name, who she was unfortunately estranged from at the time, would not have made much sense. Her only other option was to keep her legal surname of Langer, which no one else in the household had and which I imagine she had absolutely no emotional attachment to.