My fiance is Mexican so is a non EU citizen. We have known

My fiance is Mexican so is a non EU citizen. We have known each other for nearly 6 years but until this current financial year my earnings have been far too low to even bother applying for a visa for us to get married and live here in the UK with her son as well.
I have always been led to believe that it is MY earnings that are relevant to the visa application and that even if she was offered a job here in the UK that those earnings would be ignored as far as meeting the minimum income requirement of £22400 is concerned.
However I have just downloaded and been reading the Financial Requirement Home Office document dated May of this year and whilst it can get quite complex with the endless combinations what I have noticed is that it mentions quite a few times in it's case studies where the applicant's partner has been offered a job to start 8 weeks or 10 weeks after arriving and then use those earnings in the calculations.
To be quite honest I'm positive I'm mis-reading this and its talking about something else entirely so could you confirm whether if she was offered a job here in the UK would that be taken into consideration for the calculations or not?
She's a certified dispensing optician.
One final question is I will be drawing my state pension from February 2017 if my financial submission for the Visa is the tax year Apr to Apr will they only use the actual pension income received Feb to Apr 2017 (about £1000) or will they allow the annual amount because this is guaranteed income into the future!