Hi Jane1965
Your question is outside the remit of the forum, we would advise you to seek advice from your local Welfare Rights Organisation;
advicelocal.uk For Carers Allowance, you are assessed on your earnings after tax, National Insurance and half of any contribution you make to a personal or occupational pension. You can take off work expenses but only those paid and incurred as part of your work.
Self-employed earnings are usually averagedover one year unless a more appropriate period is identified (if it's a new business).
If your earnings vary, they will be averaged out over a number of weeks.
Gary