Urgent help needed please

[CNB]

I am CB, a British citizen.
My son (15 years old) has been granted indefinite leave to remain in the UK recently ( August 2018). He is year 10 student in a school. His mother has also been granted indefinite leave to remain in the UK ( march 2018).
My solicitor has advised me that they can apply for British citizenship as they have already lived in the UK for 11 years and 8 years respectively.
And they are family members of British citizen (me).
My wife has passed life in the UK and English test too.
I asked home office and they said " 12 months after ILR" . So !
So could you please advise me ?
Many thanks
cb

[CR001]

If you are British, then they can apply for citizenship now if they meet the requirements. No need to wait 12 months on ILR.

How long (11 years and 8 years) they have lived in the UK is irrelevant.