Joan Williams (Earth-3)

Dr. Joan Williams is a neurological specialist and the wife of Jay Garrick, also known as The Flash.

Early life
At some point, Joan Williams became a neurological specialist and met Jay Garrick, who needed Joan's assistance with his research. They then started to develop a relationship and got married.

Meeting Barry Allen
In 2019, Joan met Barry Allen, who arrived on Earth-3 in search for the Antimatter wall in the Speed Force. Barry later told Joan that she reminded him of someone but did not specify whom. Joan then helped Jay set up the Neural Hyper-Collider and read a poem to Barry after he fainted from the process of sending his mind to the future.

With Barry awaken, Joan and Jay brought him back to Earth-1. Iris then revealed that Joan is the doppelgänger of Barry's late mother.

Crisis on Infinite Earths
On December 10, 2019, Joan, along with countless individuals in the Multiverse, were killed by Antimatter during the Crisis,

Abilities

 * Master Neurologist: Joan became a neurological specialist at some point and assisted the creation of the Neural Hyper-Collider, a machine capable of sending humans minds across time.
 * Medical Knowledge: Joan was able to help Barry recover after fainting.

Former Equipment

 * Neural Hyper-Collider: Joan and Jay Garrick created the Neural Hyper-Collider in order to send individuals' minds to the future. Barry Allen later used the device under the two's guidance in order to understand what caused an Antimatter wall in the Speed Force.