"Following that the estate is divided between his 3 children. He was not married at the time of death and has 2 adult dc and my minor Dd."
I just saw your update.
Since there is no will, the person sorting everything out and applying for probate is called the administrator rather than the executor - but it's the same thing.
The administrator can only start dealing with the estate after they have got probate.
As he died intestate then, in this situation, everything is left equally to all the children.
Despite what a PP said, you can in fact do a Deed of Variation in the case of intestacy.
Basically, each of the adult DC need to sign a Deed of Variation saying that they give their share to your DD. This needs to be done within two years of the death.
The administrator will be the trustee and they will be responsible for looking after the money.
However, the administrator can appoint other trustees as well. From what you have said they would want you to also be a trustee.
As I mentioned in an earlier reply, the money would then be held on trust for your DD. The trustees can apply money from the trust for the benefit and maintenance of your DD as they see fit.
The capital is not your's but is held on trust for your DD until she is 18. Any money from the trust is not your income but is money coming from the trust for the benefit of your daughter.