Thank you for your suggestion

My husband and I have given the matter a lot of thought and decided that we needed to be absolutely sure every penny we donate will be used to benefit the cause we care about. This cannot be guaranteed where charities are concerned as the admin costs and begging letters are paid for by the money donors give them.
Our vicar daughter's church does an excellent job helping children who are in need of care and support. We give money on a regular basis to fund it, but know the substantial sum we are prepared to donate to mark our 50 years of marriage will be very helpful and all the money will be used for this purpose.
We will still give donations to charities, possibly the one you have mentioned.