Spouse visa requirement for salary and accommodation

[UK2030]

Hello everyone,
I hope someone can help me. Asking on behalf of a friend.

1: My friend will be getting married in February 2022. She earn more than the required amount ( 18600£). But in February she will have one week unpaid holidays as she is getting married abroad. Due to this unpaid leave she will receive less than usual salary in this month. And if we multiply February salary payslip for whole year, this will be less than required amount ( 18600£). All other months she earn more and easily match with required amount. She also have contract with employer where her salary is mentions as per annum and it is more than 18600£.

So my question is, will her contract can cover this or Home office will ignore this and will consider her February salary payslips to decide about amount required? Would she match the required amount or not ?

2: She lives with her mother. Her mother is disabled and she get support from council. House is four bedroom. There are four people in house including mother ( 3 kids and mother).
So question is what documents she need to meet with accommodation requirements?

I will be very grateful if someone can guide please.

Thank you so much.