T1G ILR : child dependant has just one parent in the country

Hi,

I am a dependent (spouse) of the T1G main appliciant, we are about to apply for ILR quite soon. I also have a child from my first marriage, living here with us, who is also T1G dependant. She's 11 now.
Now, I see in the rules, that in order for child to get a settlement:

"Both of the applicant's parents must either be lawfully present in the UK, or being granted entry clearance or leave to remain at the same time as the applicant. "
1) Do they mean here a biological parents ? My spouse doesn't have an official responsibility over my child, he is considered as a step-parent. My child's another biological parent is living outside UK and never been here in fact.

2) When we were getting a an entry clearance 5 years ago, I recall I was providing various documents proving that child lives only with me 100% of the time. Was it a proof that I had a sole responsibility over a child? do i need to do the same now? Do I need to provide a letter from other parent, saying that he's OK with my child to get a settlement?
In the rules:
..unless (ii) The Relevant Points Based System Migrant parent has and has had sole responsibility for the applicant's upbringing

How should I prove it now, it must be very obvious now that my child lives here with me in this country, anyone already been in this situation? It's not very typical, but should not be uncommon! Please help. Which documents should i get in order to get a settlement for my child.
Thank you very much.

They had accepted that you have sole responsibility when they granted the child's entry clearance 319H(f)(ii). Just provide similar proof confirming that the situation is unchanged.

If you need to obtain the child's other parent's approval, then it will undermine your claim of having sole responsibility.