So I need to make a 3 tier baby shower cake in 2 weeks.
The only 3 tier cake I made was sturdy because I only filled between each cake.
For this one I want filled the middle of each cake so I guess that would be 3 layers of frosting. Each piece of cake being about 1.5 inches thick

Whats the thinnest the cake should be before another layer of frosting?
I don't want it to collapse or slide even through there will be supports.
Especially with Fondant being so heavy.

That's how I fill most of my cakes. Just torte each 2" cake layer in half. Use a little less filling in each layer than you would normally use in just one layer of filling and your cake won't be as fragile.

Make sure each filling layer has a dam. Allow your filled cakes to settle for several hours or overnight before covering with fondant.

Thank you Diana I apprecaite the info!
I spent too much time reading about cake diasters and I was freaking myself out