Hello Deborah
Superannuation contributions splitting is possible if various criteria have been satisfied.
Attached is a link to an ATO factsheet:
https://www.ato.gov.au/forms-and-instructions/superannuation-contributions-splitting
It is possible to transfer up to 85% of concessional contributions made for the benefit for one spouse in the prior income year, for the benefit of the other spouse, where the transfer occurs in the current income year (that is, in the year after the contributions were actually made).
The spouse receiving the transfer needs to be (for the 2025 income year) less than 60 (if they have already retired) or between 60 and less than 65 (if the have not yet retired).
Attached is a link to the pdf of the relevant form that needs to be completed:
Best regards
The Auditors Institute