With us not the children but adults are the biggest cakeveaters. Cakes like these can be made in parts which is the best and smartest thing to do if the fridge is small.
I don't believe your sister needs many customers since it will be hard to bake for all of them. What she does need is good paying customers ordering a cake like this one.
The Dragon is awesome and so is John Wick!
99 years...99 cakes?

May her dreams come true without stress. She is very creative.