Translation:Children in Denmark get their Christmas presents on Christmas Eve.
Dansk Sprognævn clearly states that:
When the subject is changed from singular to plural, "deres" is used, and not "sin". [...]
That means that when the subject one refers to, is third person plural, "deres" is used - and not "sin/sit/sine", [...]
It is common to use "sin/sit/sine" [...] especially when the sentence is long, and there is a long distance between subject and the reference. It is even more common if the object is plural. [...]
As I interpret it, it is still not correct to say "Børn [...] får sine julegaver". Therefore, I have reported this issue.