It's hard to get inside the head of a psychopath. On the surface, it seems that the Adelsons have a lot of love and loyalty for one another, but how easily was Rob Adelson cast out from the family? I don't think DA will roll on WA, at this stage. she, like CA, is convinced she'll be found not guilty. I think if at some point she realises she's stuck in prison for the rest of her life she may decide to cooperate. I also think that she may want to try and save HA. He won't last 5 minutes in jail. He's struggling with his health, stress, anxiety etc He's not even sleeping well in his beautiful air-conditioned penthouse, imagine when he's stuck in a stinking hot jail cell.... So if HA is arrested, I think that will prompt DA to flip. But then she is going to want a non-custodial sentence or a very light sentence for both her and HA and she's not going to get that. Perhaps 10-15 for her and 5 for HA for giving up WA..
Edit:
DA also has this very toxic bond with her Grandkids, almost a weird obsession with them. It's not love or attachment, just a very strange relationship and she will be looking to protect them which may dissuade her from flipping on WA. I hope she has this realistion that she is never going to see or speak to her Grandkids again and neither will she see or speak to WA, CA or RA again.