Incontience pads - pics added

I've started making some CSP's but I also want to make my mum some incontinence pads. I think they will need a PUL backing but how many layers of other fabrics and what would be best do you think? She said it not just a little, but when she starts she can't stop.
I was thinking that a BV top layer, a zorb layer, possibly a couple of bamboo fleece layers, then a PUL layer with fleece on the bottom layer to stop it slipping? Do you think that's enough or shall I add a couple of more layers....and possibly about 15 inches long

update

I've made one today. 15 inches long. I used bamboo velour top, a layer of zorb, 2 layers of bamboo fleece, a layer of PUL then fleece at the bottom. I couldn't find an old towell to cut up today but I know I have one. I have given it to my mum to try and test it.
I found the PUL really hard to work with but it's a hidden layer so at least you can't see it!!!

a tip Ems gave me when i was making similar was to use an old towel or something as the first inner layer above the zorb as old cotton absorbs much quicker, and it's on the inside so noone knows it's not pretty!

i can't remember what i ended up using but it was something like bv / towel / zorb / b.fleece / fleece backing. i planned on using pul for backing but at that point i hadn't worked out how to get my machine to sew pul without it moving everywhere, so ended up with fleece.

afaik it worked fine, you could give her one like that to try, then if it's not enough to add an extra layer of either zorb or b.fleece.

excellent thank you