Expenses outside Will
You should make your client aware that only legitimate testamentary expenses (such as funeral expenses) or legacies left under a Will can be agreed by an executor. Charities do not have the same freedoms as a private individual to give away part of their entitlement – charities are much more constrained in what they can agree to because they may not lawfully expend their funds other than in support of their charitable objectives. Any request outside of this can amount to an ex-gratia payment and if this is the case, the consent of the Charity Commission will have to be obtained.
To avoid any doubt, if your client wishes to make financial provision for a headstone or memorial, they should make this clear in the terms of their Will.