A 17-year-old girl has been charged with the murder of her 10-year-old sister in Lake Macquarie, NSW.

The alleged stabbing took place in their home on Monday, resulting in the younger sister's death despite emergency efforts.

The teenager has been arrested, charged with domestic violence murder, and denied bail.

She is scheduled to appear before a children's court on Tuesday.

This incident marks the third fatal stabbing in NSW within four days, following events in Narromine and Quakers Hill.

The Homicide Squad is investigating the case, and the community remains in mourning over the series of violent events.