Meredith Grey has had a rough year, right? She’s lost two mothers. But what I want to talk about is how those mothers treated her- and her relationship with them- when they were alive.
Ellis, Meredith’s biological mother, was a career woman. She resented Meredith both for hurting her career and for hurting her relationship with Richard. The show tells the viewers that Ellis’ treatment of Meredith as a result of the resentment directly causes Meredith to be so screwed up. Through Ellis, the message could be construed or read as partially corroborating the idea that mothers who work instead of taking care of their children cause their children to be screwed up. They are Bad Mothers.
However, there is more to Ellis, obviously. On the show, she had Alzheimer’s and so rarely recognized Meredith. We see Meredith as a daughter taking care of her mother in spite of their previous issues- indicating that Meredith still hopes their relationship can be repaired and also that Meredith wants her mother to know and care about her.

In the episode where Ellis is lucid for a day, she tells Meredith she is disappointed that she hasn’t chosen a specialty and she seems to care about her relationship with Derek more than her career. She calls Meredith ordinary. Here again we see Ellis presented as a Bad Mother: she does not seem to care about her daughter’s happiness, and she advocates to both Meredith and Cristina that marriage and childrearing are incompatible with a career as a surgeon- she advises her child against motherhood and says if she wanted her same career she wouldn’t have had children. At the same time though, she does express regret that she chose to put everything into her career instead of investing time and energy into Meredith.
Meredith gets closure in the weird “afterlife” episode, where her mother (somewhat uncharacteristically) hugs her and tells her she is “anything but ordinary.” So cliche, but the show had to fix Meredith somehow, and since her mother was the source of the problem, her mother had to be the solution too. Ellis is an example of a mother not to be emulated, as she puts Meredith down and fails to show she cares up until that last moment of closure.
Susan, on the other hand, wants to be a part of Meredith’s life, and she tries so hard that she almost smothers Meredith. She buys groceries for the interns’ house and shows up unexpectedly and tries to repair Meredith’s relationship with her father. While her motivations may be somewhat out of guilt (for having persuaded Thatcher to never contact Meredith), she was genuinely trying to be a mother to Meredith. Meredith didn’t know how to respond, but it was clear that she was receptive to being “mothered.”
Were Susan’s tactics enough to have her actually take on the role of “mother” to Meredith? She certainly did motherly things, but her place in Meredith’s life was fairly shortlived, and it seems to me that nothing she did could have repaired or built a relationship in that short of a time frame. It will certainly be interesting to see how the loss of Susan will impact Meredith. Obviously Meredith was upset at the end of the last episode, but it was unclear whether Susan’s death or her father’s renewed rejection was the underlying cause. If Meredith misses “Fake Mommy” does that make her motherhood more legitimate? Or should the viewer be judging Susan on her own merits without complicating the picture by analyzing Meredith’s mental state?
To me, Susan’s efforts, while genuinely nice and quite well-intentioned, did not make her a mother to Meredith. It seemed clear, however, that she was trying to become someone who could fill that role, which is an interesting concept on its own: how possible is it, really, to “become” a mother to an adult? Is there a space for building that kind of relationship?