Q. Is there any way I can make sure emulsion stick on the wall of my daughters bedroom as she is always changing and pulling off posters etc and the sellotape pulls the paint off at the same time. 

A. The only way I know is to apply an emulsion which has a very strong bonding agent like E-B (Emulsa-Bond) mixed in to it. You need to stir in about 25% E-B into your first coat of emulsion, (it does not matter whether it is matt, vinyl or whatever) Then apply the paint with a roller or whatever and I would be fairly certain based on my experience that you will not pull that paint off, even with repeated pulls of tape etc. This is a great idea for anybody that wants to paint a wall that may be used for sticking up posters etc.