SIPP after retirement and unused annual allowance

My wife retired this year (September) now receiving a DB pension, having earned approximately £10K in income this tax year. I'd like to gift her some money to pay into her SIPP. I believe her pension annual allowance for this year will be £10K, so I think I can just work out how much pension she has contributed in her DB scheme from April to September and the remainder I could contribute into her SIPP. She also has unused allowances from previous tax years, but I'm unsure as to whether I can use these to contribute more? Please could you clarify? Thanks

Hi ,
 

Please have a look a the guidance at : Check if you have unused annual allowances on your pension savings  , which includes a calculator.  If there is a surplus, this can be added to the threshold for the tax year in question and the new threshold used for tax relief on the pension payments. Thank you .