@wouter hi!
Sry for this silence period - crazy and hot month behind us. 
So I tried today different actions, different users on different computers.
On my laptop:
- for me everything is still forking as it should
- logged in with daughters Epic account and on my laptop revision control for her is working
Then I tried on daughters computer:
- Using her Windows user tried to log in UEFN with her and my users - same result - revision control is not available
- Then I created different Windows user which is not tied to any Microsoft account (thought mby that could be the problem as she has some restrictrions on her Microsoft account) but still the same result - revision control is not working not with hers not with my Epic account.
So at this point it seems that problem is computer itself, but… do you have any clue what could be the problem?
As I stated at the beginning reinstalling Epic Launcher and UEFN did not help.
Maybe there are some log files or registers that I need to delete manualy after uninstalling and before installing everything again?
Any help as always will be apreciated. Both of us have free upcomming month and a half, would be nice to make some games together also.