FWIW - this is available in FTM
Add the Fact to one person
Add appropriate citations to the fact.
Select the Fact
Right Click - Copy
To right-click paste is a bit involved.
FTM will paste to parents, siblings, spouses, children of a selected person.
Within the above family members of the person that copied, just immediately Right Click Paste and select the family members. The Fact and all attached citations will paste to the appropriate family members.
If the person is a nephew, for example, pick one of the above in that nephew's family, select any fact, right-click, paste, and get the listing of that person's parents, siblings, spouses, and children - to include the nephew.
FTM has many other advantages over the on-line prsentation, not the least of which is providing a backup to the on-line tree, more advanced reports and data-management capabilities (like centralized Places management).