Dinah Drake

This is the third Dinah we've met, and who has the name of Laurel Lance's mother. Sounds convenient.

"My real name is Dinah, Dinah Drake". While this moment in the latest episode made me smile it also made me suspicous. Dinah Laurel Lance and now Dinah Drake, and Laurel's mother is Dinah Lance and I'm like 92% sure her full name is Dinah Drake-Lance. While it could simply be an oversight on the producers behalf, for Laurel, Laurel’s mother and Dinah Drake to all have the same first name, seems very coincidental until it dawned on me. Could Dinah Drake actually be Laurel Lance's mother? What if Dinah Drake is going to go back in time and meet a younger Quentin and conceive Laurel and Sara? True Dinah Lance is a human historian while Dinah Drake is a meta-human cop but there is one answer. 

Martin Stein

Martin didn't have a daughter before and now he does after interacting with his younger self, yet he remembers the original timeline where he didn't have one.

Time travel interventions sometimes cause younger versions of characters to live different lives as than their present day counterparts, resulting in the present day versions of themselves gaining memories of both timelines, Professor Martin Stein is a prime example of this. When Martin boarded the Waverider for the first time he had no children then interacted with his younger self in 1987, and he fathered Lily even though Martin himself never technically did this. After this Martin gained the memories of his younger self raising Lily while he still remembers his own timeline where he never did. I think both Dinahs could be the same person and here’s how it could work based on the established laws of time travel in the show. 

White Canary

It would be good story material for Sara, lecturing Martin about creating a time aberation when she herself, and her sister, are aberrations.

In the original timeline Dinah was an ordinary person who was born and raised in Central City sometime in the mid-80s and lived a life as a history professor. This would be a life where Laurel and Sara never existed as she never met Quentin, so Oliver never met the love of his life and there were no Canary vigilantes. I think somehow Dinah ended up back in the early-80s as an adult, possibly because of an intervention on Rip Hunter's behalf, with no means of return, and moved to Starling City to start a new life. There she met Quentin Lance and fell in love with him, and raised two daughters with him named Laurel and Sara, effectivley creating abberations. To avoid altering the fate of her younger self Dinah would have stayed away from Central City for the better part of her life, and if the timeline wasn't further ruptured the time loop may have remained intact.

Eobard reveals his identity to Eddie

Eobard Thawne has already ruptured the natural flow of history, so this could have affected Dinah's past as well.

However the arrival of Eobard Thawne/Reverse-Flash and him murdering Nora Allen, Harrison Wells and Tess Morgan in 2000, unleashing the particle accelerator in 2013 Central City, and everything else caused by his very presence during those 13 years, ruptured the timeline and could have done so enough to deviate the younger Dinah's life and she became a cop instead of a historian, and became a meta-human. Apparently in Eobard's timeline the particle accelerator wasn't built until 2020 by Harrison Wells and Tess Morgan themselves, and in Starling City not Central City. As a result the younger Dinah’s history will be different from her older self and will now be a meta-human vigilante working with Green Arrow as the successor to the Black Canary mantle, while her older self is still a historian living in the wrong time-zone. However I think the younger Dinah will still go back to the mid 1980s, maybe because she learns of her relation to Laurel and Sara, and meet the younger Quentin and conceive the sisters to restore the timeline. 

Black Canary (Laurel Lance)

Wouldn't it be cleverly faithful if Laurel's successor was her own mother? Though I do still hope to see an Earth-2 Laurel reform later on.

However this Dinah will have lived a different life to what older Dinah herself did as a cop/vigilante and not a historian, so the present day Dinah’s memories will change. Now she’ll have memories of a life as a time displaced historian and one as a time displaced vigilante cop. As the younger Dinah in this timeline became a meta-human chances are the older Dinah herself will become one too to align with the timeline. No doubt present day Dinah would then visit Oliver to clarify the time loop. What would be further awesome is if Oliver himself traveled back to the early 90s, to ensure everything is as it should be and give a proper goodbye to Dinah until she meets him again in 2017. What would be heartbreakingly sweet is if Oliver actually met Laurel's child self during this visit and encouraged her first meeting with Oliver's child self in this new timeline, as Laurel mentioned once that she and Oliver had been friends since childhood. Oh my god the feels! 

I know this may be a bit far-fetched but come on! Dinah Drake has the same first name as Laurel and her mother in a universe of shows with time travel, Multiverse and magic when it’s a known fact that Dinah Drake is traditionally Laurel Lance’s mother? That sounds like way too many coincidences and if this isn't true there has to be some reason for them having identical names. 

Dinah Lance

Also Dinah is River Song in a universe of shows where Rory Williams is Rip Hunter. Why wouldn't they try something like this?

Wouldn’t it just be the most awesome way to stay faithful to the comics whilst putting their own twists on it if Dinah Drake became the successor to her own daughter’s mantle? It would also be good story material for Sara if she learns she and her sister are aberrations themselves, when she's been lecturing Martin about creating one with his daughter. It could also be a way for Earth-2 Laurel to reform if she interacts with her mother's Earth-1 counterpart. We also need to remember one thing as well. Dinah Lance is played by freaking River Song, in a universe of shows where Rip Hunter is played by Rory Williams and Malcolm Merlyn is played by Jack Harkness, so this theory sounds completely plausible for those reasons alone.