well, this is very intereting... I am in flight savety the last ten years and I saw different versions...
...some Airlines require 3 other only 2 passengers per EXIT
...some Airlines require on the (e.g.) B737 only fit passengers in the first row +overwing; other carrier demanding fit passengers in the front AND
last row + overwing
...some carrier operate with a MINIMUM 16 yrs. limit
...some carrier call their ABP instead PSP
-Pre Selected Person
...most carrier operate with the policy, that family can fly in row one, if there is a bulkhead!, but have to stow for take off and landing EVERYTHING in the bins
...some carrier uses the last row as normal seats, but for emergencys, these passengers have to move away and switched for more reasonable ABP
...some airlines have the policy to operate all exit with at least ONE passenger, other doesn't...
...some airlines will give you prior to depature a personal lessing-hour, how to open the exit and how to behave, other doesen't
and on, and on, and on... (I can talk about this for hours...
>> You see, it depents on the airline AND
their national authorities