Extension of partner’s visa after five years if they haven’t met requirements for ILR yet

Hi I submitted application for ILR to myself and two children under 18. I wasn’t able to include their mom, my wife, in the application as she hasn’t met the requirements for ILR, namely the English test. The home office responded that My application would not be decided upon because the kids wouldn’t be granted ILR because their mom hasn’t applied ILR or had it previously. They recommended their application to be changed to visa extension instead till their mom has had ILR, otherwise the appplication would be rejected with no refund. I’m not sure how to apply for my kids and their mom if their BRP along with mine end in this July, three months time, and Obviously I haven’t had my ILR granted because of this. I don’t know whether it’s possible to apply for my wife, along with kids if they already have passed already 5 years on a tier 2 dependant visa And where on the website.
Is anyone available to advise please?

Your wife and children all need to apply for PBS Dependent extensions. There is no limit on the number of extensions a PBS Dependent can apply for.

PBS Dependent children cannot get ILR if both parents are not applying for ILR at the same time or if one parent already has ILR and the other parent is applying with the children.