Board Thread:General Discussion/@comment-24979796-20140527195418/@comment-5278765-20140619223937

Yeah, like with the Alzheimer's.

Maggie's not her sister. That's the difference. Maggie was given up for adoption, so she's not part of the Grey family anymore. Thatcher left Meredith with her mother and started up a new family. Ellis had a baby and gave her up for adoption. Not the same thing. I am fairly certain that Ellis had nothing to do with her after she was given up, so Meredith wouldn't know her name because her parents would have named her.