Inviting my unmarried partners child to the UK

Apologies if my question has already been answered before but I have spent some time browsing the board but have not found anything quite close to my situation:
I have an ILR, and
My unmarried partner has been granted limited leave to remain because she has a British child in a prior relationship. Also, she has recently had another child for me too.
She has a 17 year daughter abroad, she is trying to invite her to the UK as a child.
We started the application for the child from
https://visas-immigration.service.gov.u ... ype/funnel, then selected

"*Join or accompany a family member, who either is already in or will be travelling to the UK, the Channel Islands or the Isle of Man (and you cannot apply on any other form)" then selected

"A British citizen settled in the UK or in the UK for another reason"
and the application came the under the below category:

"Non-British child of a parent granted or currently applying for permission to enter and stay in the UK, as the parent of a child who is a British citizen, settled in the UK, or in the UK with pre-settled status under the EU Settlement Scheme."

The Appendix that was suggested under the above is Appendix 2 of VAF4A, however, the more I go through this Appendix the more I feel it's the wrong form as it's not asking anything related to our case.

I was also under the impression that I wanted to do the application under Paragraph 301.
Questions;
1. Could someone please tell me what will be the right appendix or the right form?
2. With my partner's circumstance, has she got any ground to invite her daughter if under what category?

I think if you are British or settled, then they may treat her as your partner instead of a parent. Her child is subject to Appendix FM, including E-ECC.1.6.

One of the applicant’s parents must be in the UK with limited leave to enter or remain, or be being granted, or have been granted, entry clearance, as a partner or a parent under this Appendix (referred to in this section as the “applicant’s parent”), and

• (a) the applicant’s parent’s partner under Appendix FM is also a parent of the applicant;or
• (b) the applicant’s parent has had and continues to have sole responsibility for the child’s upbringing; or
• (c) there are serious and compelling family or other considerations which make exclusion of the child undesirable and suitable arrangements have been made for the child’s care.

So, Appendix 2 of VAF4A seems correct. But is child eligible?

Thanks, Vinny. that's the dilemma am in right now as Appendix 2 of VAF4A doesn't seem to be asking questions relating to spouse or child and I was wondering if I was on the right track or not.