It may still be that he did not need probate. It all depends.
He owned a house with his wife, he had bank accounts and shares so it sounds like he might need probate
If the house was owned as joint tenants (between married couples this is most common unless one of them insists otherwise) then the house automatically passed to his wife. Same with the savings and shares if they were jointly owned. If you’ve been estranged from your dad for some time it’s hard for you to know whether his estate would need probate.
Here is the info off gov site.
You may not need probate if the person who died:
^^
only had savings
owned shares or money with others - this automatically passes to the surviving owners unless they’ve agreed otherwise
owned land or property as ‘joint tenants’ with others - this automatically passes to the surviving owners
I don’t think there’s any harm in disclosing the children’s dates of birth, but I don’t know why she needs it.
I think as the parent of a minor you can act on their behalf to ask to see the will.
But, ask yourself what do you want to find out? Do you think there’s a will and she’s not dealing with it correctly (because you could also be a beneficiary)?
Or is it actually just good news that the DC will get a bequest from your dad and leave it at that?