Hi Pink105 Pink,
To work out if your income is over the threshold for child benefit, you'll need to work out your 'adjusted net income'.
Your adjusted net income is your total 'taxable income' before any allowances.
As your armed forces pension, in respect of injuries sustained in service, is not taxable; it should not be included when calculating your adjusted net income.
Please have a look here:
High Income Child Benefit Charge
And what counts as income here
Income Tax: introduction
Thank you.