I did a side quest with Anna and talked with her, but she never joined my party for some reason. Does she join right after the battle? I also have 3 DLC based characters, does this prevent her from joining?
She joins after Gaiden 4 or during it or something. You were probably playing Gaiden 2, where she shows up but can't be recruited yet. I'm not sure what the relevance of talking to here there is, but it's probably part of building up towards that.
TheOthin thanks for the info. I believe your are right. These gaiden missions pop up in odd chapters don't they, I need to pay attention to the Gaiden chapter title more than the actual chapter I am in.