Is anyone good at making up riddles?

[MrsH2017]

Ok, so this is a long shot but I'm really hoping there is someone creative on here that can help me!
I'll be announcing to my 10 year old that she's going to become a big sister again in June. She LOVES riddles, so I thought that would be a really fun way for her to find out. The answer will be hidden inside a locket.

Can anyone think of a riddle - easy or hard, that i can use?

Many thanks!

This is going to need you to jiggle,
and there will be a lot of piddle,
but the smiles and cuddles will drown out the niggles and your sure to be first to get giggles?

Disclaimer I'm very tired and bouncing a baby who will not go to sleep so this is probably shit.

My niece is the same and I'm constantly talking in silly rhymes!

I love this!! Thank you so much!! :-)