Why can’t I play as a grandkid

I’m so sad! I had two daughters who died young and now I can’t continue the legacy. One daughter died at 19 in a car accident. The other died at 22 from cancer. She was married with a baby at this time though. I don’t understand why the game makers won’t allow us to continue on as our grandkids! 😭

I am a 55 year old woman so I can’t have any more children - devastating.

UPDATE I prayed for fertility and gave birth to another daughter at 56 years old - then the following year I got a pop up to adopt a friend’s 11 year old daughter so I’m set :) But still, wish I could have just played as my grandson.