A really nice idea for a quiz but a few errors I think - Britain had female heads of state and government from 1979 to 1990, which was well before Estonia, and Portugal abolished its slave trade under pressure from Britain, which had already abolished her own slave trade some years previously. Just the two I'm aware of!
I wonder also if the "modern parliamentary session" needs clarification - I'm not sure what it means?
I wonder also if the "modern parliamentary session" needs clarification - I'm not sure what it means?
As mentioned above, Britain had a female head of state and PM in 1979, before Estonia existed.
Also (since I assume you're referring to Catherine I), Great Britain had a female queen (Elizabeth I) long before even that.
I think it's fair to say that monarchs of previous incarnations of modern countries don't exactly count for this.