I have a client coming to see me this afternoon. She wants a christening cake for next week but she wants it by Wednesday/Thursday. Then she is going to take it to another town and they are only going to use it on the Sunday. How can she keep the cake fresh if it is covered in fondant and not allowed to go into the fridge or freezer? Please help?

Did she give any reasoning for wanting to do this?

I think that is way too long. IMO the cake should be eaten by day 4. If you bake on Tuesday and it's not eaten until Sunday, thats 6 days..... a LONG time. I wouldn't do it. Don't be afraid to say no when your reputation is at risk. If the cake is bad she will probably blame you.

Is this the timeline?
she picks it up on Thursday and serves it on Sunday
You bake on Monday or Tuesday and put it in the freezer at least overnight.
You fill and use the ceramic tile trick to get the cake to settle faster, frost and cover and decorate on Wednesday.
Actually it should be fine.

There's NOTHING about putting a cake in the fridge that keeps it fresh. Refrigerating cakes actually dries them out. Freezing keeps them moist.

Also use a wash, and of course do not use a filling that requires refrigeration.

Thx. I think I will pass on this one as it is very hot at the moment and I do not think the cake will last that long.
I do not want to sound stupid, but what is the ceramic tile ....?

You place a tile (or anything heavy) on top of your cake (after crumbcoating). I don't crumbcoat the top, then I put a cardboard round between the tile and the cake. This helps the cake to settle before you ice it. Anything that is going to shift or smush around is going to do it at this stage and not after you ice it. This was the ONLY thing that solved my buttercream bulge problem. HTH