Thank you for your query.
As your partner is under the transitional provision, to apply for ILR one of the requirements you need to meet is adequate maintenance.
I will provide you with guidance form which tells you how to assess adequate maintenance. The guidance can be found here: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/452964/IDI_Adequate_Maintenance_and_Accommodation_Part_8_Annex_F.pdf
I refer you to the following section of the guidance:
3. Assessing adequate maintenance
3.1. How to assess adequate maintenance
The Upper Tribunal case of Ahmed [benefits; proof of receipt; evidence] Bangladesh 
UKUT 84 [IAC] directed the Home Office to evidence financial figures in all decision letters in
which refusal was based on inadequate maintenance.
Therefore, decision makers considering an application for entry clearance, leave to remain,
further leave to remain or indefinite leave to remain which has to meet a requirement for
adequate maintenance must set out the financial position of the applicant/sponsor in all cases
that fall for refusal using the following formula:
A – B ≥ C
A minus B is greater than or equal to C.
A is the net income (after deduction of income tax and National Insurance contributions);
B is housing costs (i.e. what needs to be spent on accommodation); and
C is the amount of Income Support an equivalent British family of that size can receive.
The decision maker must take the following steps to assess the adequacy of the funds
a) Establish the sponsor’s and/or applicant’s (if they are in the UK with permission to work)
current total weekly net income (A).
If the net income varies, calculate a weekly mean average.
Include all net income currently received, including benefits currently received to which
the person is entitled, and including third party support.
An entry clearance applicant may say they will be entitled to claim public funds in their
own right in the UK, e.g. under reciprocal arrangements between the UK and their home
country, and ask for this to be included in their net income. However, any potential
future entitlement to benefits after the applicant arrives in the UK does not count
towards net income when assessing adequate maintenance.
Where there are permitted cash savings, include a weekly equivalent figure (see 3.2).
b) Establish the sponsor’s current weekly housing costs from the evidence provided (B).
c) Deduct the weekly housing costs from the weekly net income (A).
d) Calculate how much a British family unit (of equivalent size to the sponsor and their family
unit) would receive if they were in receipt of Income Support (C).
For details of current benefit rates see the document at the following link: http://www.rightsnet.org.uk/pdfs/rightsnet_benefit_rates_poster_2015_16.pdf · Decision makers must always use the correct rates which apply at the date of their decision. Case studies in this guidance show the method for setting out a calculation and do not necessarily represent current rates. e) Compare the weekly net income after deduction of weekly housing costs with the equivalent level of Income Support using the following formula: A – B ≥ C A minus B is greater than or equal to C Personal debt, including loans and credit card debt, should not be taken into account in this assessment. Only the weekly housing costs are deducted from the weekly net income. Where the weekly equivalent of income or housing costs is calculated to part of a penny, decision makers should always round this figure down.
So you need to follow the A – B ≥ C formula to assess as to whether you satisfy adequate and maintenance.
Please kindly rate my answer.