She was the daughter of Morris Rosen, who in 1912 lived at 25 Brunswick Street, London.
She boarded the Titanic at Southampton with her baby son Frank Philip Aks (ticket number 392091, £9 7s). Leah and "Filly" had left their home in London for 195 Chapel Street, Norfolk, Virginia where Leah's Husband Samuel, a tailor, was waiting for them.
On the night of the sinking Leah Aks was forced up to the boat deck she found herself next to Madeleine Astor. Upon seeing the baby Mrs Astor removed her shawl and wrapped it around him. Not long after as Leah stood on the deck clutching her baby son he was suddenly torn away from her and tossed into Lifeboat 11 which was being prepared for lowering, as she struggled to retrieve him she was restrained by crewmen who thought she was trying to rush the boat. Baby Filly was caught by Elizabeth Nye who sat him on her lap, later she wrapped him in a steamer blanket to keep him warm. Meanwhile Leah, still on board the sinking Titanic and in a state of shock, was pushed into Lifeboat 13 next to Selena Rogers Cook.
After their rescue Leah and Selena were walking together on the deck of the Carpathia when an Italian woman (possibly Argene del Carlo) passed them holding a baby, Leah recognized Filly at once. She went to Captain Rostron and appealed to him to help her get her baby back, he took the two women to his room and asked each to provide proof of identity. Leah was able to describe a birthmark on Filly's chest and he was returned to her.
She was so grateful to Captain Rostron of the Carpathia for her rescue that the following yearly giving birth to her only daughter she named her Sarah Carpathia Aks. But the nuns at the hospital, when filling out her birth certificate, put down Sarah Titanic Aks.
The bitter cold she had endured in the lifeboat while awaiting her rescue had permanently damaged her eardrums, and she suffered from a partial loss of hearing for the rest of her life. Mrs Aks died on 22 June 1967 and was buried at Forest Lawn Cemetery, Norfolk, Virginia.