Speaking to TV Guide at San Diego Comic-Con on Sunday, Frain revealed that Amanda Grayson will make an appearance in the rebooted series — at least, in the backstory elements to explain how his relationship with adopted daughter-slash-Spock's sister Michael Burnham (Sonequa Martin-Green) came to be.
"I think we've only just started peeling that back," Frain explained. "What we start with is Sarek's mentoring of Michael and his attempt to find a place for her. There's a little bit of backstory that starts happening about how she became involved in his life. And then Amanda comes in — in the last episode I shot, she had just been introduced, so I'm pretty sure we're going to be finding out about that. But I haven't read the last five episodes, so I don't know. They come in very late."
In the original series, Sarek and Amanda were Spock's parents, who bridged the interspecies divide to form a Vulcan-Earthling relationship to span the generations.
Star Trek: Discovery premieres Sept. 24 on CBS before moving exclusively to CBS All Access.