Bren,

Did it suddenly take you to the Adoption Screen with all the grown up children, or did you press the New Generation button?

There's a message that appears on the screen once both parents pass which explains what your choices are from that point forward, while showing you the Family Tree and the New Generation button. Did that message not appear for you?

I actually had Delilah still living at home when Peach and Mac both passed, and thought about letting her grow up alone, but decided against it and went ahead to the New Generation.

LadyCFII gives an excellent explanation on VF & the choices it offers here.

I hope this helps you in your next generation!