Minor interest how to protect?

Deceased died intestate. Eldest daughter and the Minors dad are appointed as PR and Trustees

How do i transfer the eldest childs share of the property to them and at the same time hold the remaining 50% by the Trustees. How do i register this in practical terms is an AS1 sufficient if so what is the wording for the minors share?

I will also register a restriction to protect this interest.