ILR Dependent to ILR

Hello,
My wife entered UK as ILR dependent and below are the Type of permit specified on the biometrics.

Feb 2016 to Mar 2016 - Entry clearance
Feb 2016 to Nov 2018 - Leave to Enter
Dec 2018 to July 2021 - Leave to remain

She would complete 5 years in UK as ILR dependent in Feb 2021, and assuming all other conditions are met, i had following queries..
a. Does the initial visa issued as "Leave to enter" count towards the 5-year period in UK ? I.e she is eligible to apply for ILR by Feb 2021..?
b. Would the application still be SET(O) ?

My ILR was based on the Tier-2 and 5-year route.

Your inputs are highly appreciated..

What visa your wife has? Check her BRP. Spouse visa OR PBS dependent?

Did you have ILR before she came to UK?

Her current BRP states SPOUSE/PARTNER LEAVE TO REMAIN while the earlier BRP stated SPOUSE/PARTNER LEAVE TO ENTER. Yes i had an ILR (since 2013) before she came to UK.

She can apply when she completes 60 months minus 28 days from the date she entered UK. She will apply on SET(M) - not SET(O).

Thanks for your help and inputs.. You're a Star !! Much appreciated..