This one should be easy for our friends across the pond. Let see if some North American can find it fast enough.

What year did Elisabeth bore the full weight of regal as she performed many of the official duties of Head of State?

Is that regal responsibility/power/regalia (boredom, even ) ? There's a word missing .

oops! That would be "regal office" Fred.

And she's 'Liza with a zee, not Lisa with an ess' too, but we'll give you that one as a typo

Need a clue? It was before 1952.

Hi Mozart,
I think it was 1942. That year, she became Colonel-in-Chief of the Grenadier Guards, and carried out her first official engagement when she inspected them on her 16th birthday.

Biography Channel

Nice finding dg, but not what I was looking for. EliZabeth (thanx Fred) had to replace her father the King at some point who was absent for regal duty ( office). But it wasn't in 1942 as you pointed out ( real closed).

I don't think anyone will get this one ( points for me ).

Princess Elizabeth decided it was time to show that she was ready to assume the full weight of her Royal responsibilities. Realising the need to boost morale, she became patron of organisations whose work she valued. Already President of charities such as the Queen Elizabeth Hospital for Children in Hackney, east London, and the National Society for the Prevention of Cruelty to Children, she embarked on a series of national visits with the King and Queen. She first bore the full weight of regal office at the age of 18, in 1944, when, during the King’s absence on a tour of the Italian battlefields, she performed many of the official duties of Head of State.

Good question, Mozart. It was a difficult one