Life interest or burden on title

Would like to know if the following is a life interest or a burden on title

I will devise and bequeath my dwelling house at O' Connell Street, Dublin to my executors and trustees on trust for my daughter Mary, in the event of her dying I direct that after her death the dwellinghouse shall be sold and the proceeds of sale shall be divided amongst my 3 children

After the death of the testator, should the folio be modifed to reflect either the life interest or the burden, or is it ok not to do anything.

If the executor dies or is mentally ill, I presume the executorship passes away, that it does not go to their executor, but that the next in line has to apply to be executor, or how does it work.

Is there any reason why the property would be transferred from the testators title to the executor.

That creates a trust, where the trustees will hold the property for the benefit of Mary, and after her death to sell the property.

What should happen is that the trustees become registered as owners of the folio with an inhibition to protect the beneficiaries.