Hi Sue. The charity that runs the Every Head Should Have a Bed campaign get their beds at subsidised cost directly from retailers and don't, as far as we know, accept donations from the public.
There are, however, organisations that will accept furniture donations. For example:
The Furniture Donation Network
Alternatively, you could sell the bed locally and donate the funds directly... https://zarach.org/donate/
Best wishes and thank you for your kind gesture.
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