Children won't take over the throne after Royal Assasination Quest

[Password.]

I remember reading few days ago, that the newest Sims Medieval patch enables an option to age-up a child and take over proffesion of his hero parent when he dies. I didn't have any occasion to try it, but today I decided to play Royal Assasination Quest and replace my boring King Cenred with his daughter, Princess Amerei. I killed a monarch with a spy (who was also Amerei's mother) and when I wanted to select my princess to replace him - she wasn't there. I could only create a new king or choose one of the default ones. Luckily I saved the game before, during the quest, and my Cenred is not gone forever yet. But I'd still prefer his daughter to take over him...
Do these children age-up or not? After reading many different opinions on different forums I'm super confused. Is there any way I could make Amerei a queen?

<sorry in advance for any possible grammar mistakes, my english is not the best>

[Rynorean]

It worked for me when I did the quest.

You have to complete the quest first.

After it is finished (before selecting a new quest) click on the castle icon and it will say that you need a new monarch. You normally get 3 options - Male, Female or custom. After the assassination quest you will get also receive the option to age up a child sim as a replacement. Choose this one.

Hope it helps.