Automatically add descendents and relatives of a person to the timeline
When you select a person's event card on the timeline, pop up options would be displayed to allow the following:
Show descendants
Show family tree (i.e. all relatives)
In each case, the results would be added straight to the timeline.
As a further improvement, colour coding could be used to show the different types of family connection if desired.
Please comment if there are any other relative related options that you would like to see available in the future.
Note: The functionality described is actually already available, but is quite advanced as knowledge of Wikidata Queries is required. The planned feature will still use Wikidata to provide the relations of a person, but the system will take care of the complicated bit in the background.