I think Holly has been secretly reading Science Fiction books when no one is looking.

This morning on the way to school...

Holly:

Pretend I am a little girl and you are my Daddy.


Me:

(Guardedly) Er... okay...


Holly:

And you are holding my hand and we are going to school.


Me:

Right... So, essentially, you want me to pretend this is reality?


Holly:

Yes.

That's the plot of several of Philip K Dick's better books right there.