Hi Katriona McEwan,
There are no income tax implications on the giving of or receipt of a cash gift unless the cash gift generates interest or dividends.
These would then potentially be subject to tax. Further guidance can be found here (Tax on savings interest
andTax on dividends
You may wish to consider inheritance tax implications where the cash gifts exceed £3000.00 in a tax year.
(How Inheritance Tax works: thresholds, rules and allowances