In 1939, Louisa's grandparents made the decision to give her mother, Channa, away "in an attempt to save her life."
Louisa posted the picture to her Instagram and explained some of her family history.
She captioned the post: "This first picture is my grandmother and my mum. Taken in 1939 in Amsterdam.
"My grandmother and grandfather made the impossible decision to give my mother away in a desperate attempt to save her life.
"It paid off through nothing more than luck.
"The second picture is of my mum and my sister and myself.
"Today and everyday I remember my grandparents' bravery #neverforget #neveragain #holocaustmemorialday."
Friends and fans commented on the post.
Sandra Marvin, who played Jessie Dingle in Emmerdale, commented a yellow heart and praying emoji along with three kisses.
One follower wrote: "Louisa your grandparents must've been remarkable people."
Another commented: "Brave people that made a tough decision."
Louisa went onto share a bit more of her family history, as she remembered her Great Aunt Els.
Louisa wrote: "My sister and I embarked on a project last year to discover some family history we knew very little about.
"Knowledge is power and we never wanted these stories or people to be forgotten.
"But it was unbearably painful and today I remember Els. My great aunt.
"A famous and brilliant dancer and fierce woman who was brutally murdered.
"The documentary will be transmitted in the springtime and I'll post details as to when when I know. #holocaustrememberanceday #neverforget #neveragain #holocaustmemorialday."
Last year Louisa spoke at the Holocaust Educational Trust conference about her mum's experiences and that she had been hidden by a non-Jewish family in the Netherlands until the age of five.
Louisa is best known for her roles in Judge John Deed and Emmerdale.
In Emmerdale, the actress played school teacher Maya from 2018 until 2019 and was the centre of a storyline which saw her groom schoolboy Jacob Gallagher.
My grandmother and grandfather made the impossible decision to give my mother away in a desperate attempt to save her life.
The teacher even began sleeping with Jacob just days after his 16th birthday.
Eventually she was caught and was sent to prison for 12 months, but ended up serving five.
When she was released it was revealed to viewers that she was pregnant and on Christmas day, she left the baby on David and Jacob's doorstep.
A DNA test proved that David is the baby's father and he decided to call his son Theo.