Breakdown of Она не делится паролями для своего спокойствия.
не
not
она
she / it (for a feminine noun)
пароль
password
для
for
Questions & Answers about Она не делится паролями для своего спокойствия.
Why do we use своего here instead of её?
Свой refers back to the subject of the sentence, which is Она. While её means "her", using it here might imply she is doing it for some other woman's peace of mind. Whenever the possessor is the subject of the sentence ("she" does something for "her own" sake), you should use the appropriate form of свой.
What case is своего in this sentence?
It is in the Genitive case. The preposition для (for) always forces the following noun phrase into the Genitive. Because the noun спокойствие is neuter, свой takes the neuter Genitive ending, becoming своего.
Why is the word for passwords (паролями) in the Instrumental case?
The verb делиться (to share) requires the Instrumental case for the object being shared. You can think of the grammar as "she doesn't share by means of passwords."
What is the difference between делить and the reflexive делиться used here?
The non-reflexive verb делить means "to divide" or "to split" something into physical parts. Adding the reflexive -ся shifts the meaning to the social act of sharing information, feelings, or resources with others.