Sentence examples for all of their from inspiring English sources

"all of their" is a correct and usable phrase in written English.
It is commonly used to refer to the possessions, qualities, or characteristics belonging to a group of people. Example: "The Smith family is known for all of their charitable contributions to the community." In this sentence, "all of their" refers to the charitable contributions made by every member of the Smith family. The phrase can also be used to show possession in a similar way to "all of their" as in, "I've seen all of their movies."