What should be considered when plastering small bathrooms?

Hello,
We have two very small bathrooms (1.50x1.50 and 2.00x1.06) and would like to plaster them from 1.20 meters upwards. Tiles will be placed in the shower and below.

Since the two bathrooms have no windows and no other ventilation, we are concerned that mold will develop quickly. How can we prevent this? Which plaster should we use and do we need to treat the walls specially and/or use special paint?

Thank you in advance for your answer.

Lime or clay plaster can regulate moisture to some extent. After a hot shower, ventilation will be necessary in these small rooms to permanently avoid moisture damage. Properly sized and installed, this is the mold protection you need.

These are mini-bathrooms. That's exactly what I'm looking for. Can you post floor plans or pictures?