This is one of the issues of inheritance and may be understood in the following ways:
If she died and left behind a father, a mother, siblings through the mother and siblings through the father,
in that case her father and mother only inherit from her. The mother gets one-sixth and the father gets the rest.
Ibn Qudaamah (may Allaah have mercy on him) said:
if there are two parents and two brothers or two sisters, then the mother gets one-sixth and the rest goes to the father. End quote. Al-Mughni (6/258).
If she died and left behind a father and siblings through her mother and siblings through her father,
in that case only her father inherits from her and her siblings do not take anything, because the father prevents other siblings from inheriting and they do not inherit anything along with him.
Imam al-Shaafa’i (may Allaah have mercy on him) said:
Neither the brothers nor the sisters -- whoever they are -- inherit anything along with the father. End quote. Al-Umm (8/239).
If she died and left behind a mother and siblings through the mother and siblings through the father
In that case the mother inherits one-sixth, because Allaah says (interpretation of the meaning): “if the deceased left brothers or (sisters), the mother has a sixth” [al-Nisa’ 4:11].
The siblings through the mother inherit one third, which they share and the share of the male is the same as the share of the female, because Allaah says (interpretation of the meaning):
“If the man or woman whose inheritance is in question has left neither ascendants nor descendants, but has left a brother or a sister, each one of the two gets a sixth; but if more than two, they share in a third” [al-Nisa’ 4:12].
What is meant by brother or sister in this verse is the brother or sister through the mother, according to scholarly consensus.
The siblings through the father take the rest by default .
And Allaah knows best.