How many layers of bamboo terry for a breast pad?

I'm going to make up some breast pads for my friend who never used cloth ones with her first 2 babies but would like to try with her 3rd baby (due April).

I have some PUL for the backing, minkee or BV for the top and some bamboo terry for the middle but I'm unsure how many layers to put. Obviously I want them to be effective in absorbing milk but I also don't want them hideously thick and put her off using them!

Any tips & advice welcome.

Thanks x

I think WN use 1??