My 1st daughter's name is Samavia (I read it is another name of Hazrat Fatima RA)

Allah is blessing me with another daughter, Masha Allah. I want to name her with 'S' referenced from Quran and I want it to be unique as well.

Please suggest names or any Sahabiah's name or any name with S related to islamic history/ origins.

Here are some good names from the Quran for girls that start with the letter S, at the end there are three that are related to Islamic history:

Sabrah means patient.
Safaa is a place in Mecca visited during Haj.
Saiha means a woman who fasts a lot.
Sajidah means a woman who prostrates to Allah often.
Salihah means a pious and virtuous woman.
Samaa means high-status and exalted.
Sakina means source of peace and tranquility
Saarah (someone who creates happiness in others)
Saalimah (good and faultless)
Sateerah (keeper of secrets)
Sajaa (calm and tranquil)
Sajwaa (calm and tranquil, calm breeze)
Sahaab (cloud)
Sahar (dawn)
Siraj (lamp, source of light)
Sarab (mirage)
Saraa (happiness and ease)
Soroor (happiness)
Suaad, Saadah, Sadiya, Saeeda (happiness and success)
Salaamah (innocence and safety)
Salmaa (like Salaamah)
Salwaa (remover of sadness)
Samaaha and Sameehah (forgiving, gracious)
Sanaabel (ears of wheat)
Sanaa (light and radiance)
Somayyah (exalted and high status)
Suham (good luck)
Saudah (lady, and name of one of wives of the Prophet SAW)
Sireen (this one is NOT in the Quran, name of the sister of Mariyya, the wife of the Prophet SAW who gave birth to the Prophet's only son Ibrahim)
Sidra (a tree in Paradise, and the name of a Sahabiyyah)