LOL, and I did not say Marlena ALWAYS was supportive. They seem to have been getting along better, since Sami stopped accusing her mom of ruining her life because of Sami spying on her mom & John in the conference room.
Right now, Marlena has been very focused on John, and Brady as well as Eric. Sami has not even inquired about John, or checked on how Brady is doing in ages. Again, she is still really wrapped up in herself, and her revenge scheme, which now no longer looks that good to her. If she had not accidentally bumped into Eric, she would not even know what happened in Rome.
She is extremely self-centered, and everything is always about her, no matter what is going on in other family members' lives, she manages to think only about herself, how whatever it is affects her. When was the last time Sami checked on her gramma, you know, the one with Alzheimer's, who is still actively running a restaurant? Heck, she has not even cared enough to keep tabs on her partner, Kate, while Kate makes sure she keeps tabs on Sami.
But Marlena knows Sami will always do what Sami wants to do. And she did NOT want her family at her wedding, which was a cruel slap in the face to them all. No matter if she was planning revenge. Big deal. Her kids were there. She put on a great show, before, and even after EJ was arrested. And why the need for a wedding planner when there were really NO guests?