Catholic tradition holds that Mary was an only child. The 'sister' of Mary mentioned as being at the foot of the cross with Mary was actually Mary, wife of Clophas, who is thought to have been Joseph's brother. Therefore, this other Mary would be a sister-in-law of the Blessed Virgin
Little is known about Saint Anne's life so it is unknown whether she had any siblings. There are no surviving records that might answer your question.
If Lucy had any siblings there is no record of them.
It is thought that Cleophas was a brother of Saint Joseph. He was the spouse of the third Mary at the cross when Christ died.
If Matthew had any siblings I can find no reference to them.
If Valentine of Rome had any siblings there is no record of them.
If Monica had any siblings, there is no surviving record of them.
Mary Cassatt was the second oldest of four siblings.
There is no mention in any biographies about any possible siblings of Patrick.
Historical records are unclear about Saint Cecilia's siblings. Some sources suggest she had brothers, while others do not mention any siblings. The focus is often on her life as a martyr and patron saint of musicians.
If Sophia had any siblings, there is no record of them.
No she does not have any siblings as far as i know
If Barnabas had any siblings we have no record of them.