PBS tier 1 dependent visa extension

Hello respected members
i came to UK in 2007 and have got PSW and then switched to tier 1
my family came in 2010 and they came on dependent visa and then we all got passports except for my wife for whom i had to apply for extension which is expiring on 16th august 2021
my question is that what form do i need to fill in to apply for her extension again as she has some learning disability and cant pass her life in uk test for a number of attempts she made before.
in order for her to pass the test i need some more time so i need to apply for her yet another extension
can you please guide me as to what form needs to be filled in and what other requirements are there to fulfil for home office.
her case history is as follows.
came to uk in 2010 as dependent of psw visa holder.
then switched to dependent of a tier 1 visa holder
extended the visa again as a dependent which will expire on 16th august 2021

thanks

DEAR RESPECTED MEMBERS
Any update on my query please

1. Does she not qualify to apply for ILR based on 10 years long residence?

2. Also useful to state which category of Tier 1 dependent visa she holds (there is more than one category).

THANKS FOR YOUR VALUABLE REPLY
even if she applies for ILR on 10 years long residency she has to pass the life in uk test which is a nightmare for her due to her limited abilities
she was on a dependent visa of a tier 1 general holder (points based system salary age qualification etc route not the enterprenual one)

i have filled her form online via the website which states that apply only in the category she got the visa as a dependent even if the main applicant has got ILR or British passport (bit confused what to do)