Am I allowed to raise money for a friend rather than a charity?

My friend has been trying to get pregnant for 4 years. She had a son when she was 20 and unfortunately he died at birth. She then gave birth to a daughter who is now 8 years old. She has since met someone new and is married to him. They are such an amazing couple yet for the last 4 years they have been unable to fall pregnant. They have had multiple tests but they both seem to be able to conceive. Because she has a daughter already the NHS have told them that they are not able to have IVF for free and they are both desperate for a child. I have seen them go from a bubbly, happy family, to a desperate, sad one. I want to raise money for them to have IVF by doing sports games, cake sales and boot sales, but I am just not sure whether or not I am allowed to because it is not a registered charity. What can I do? I really want to help them so I would appreciate any help with this. Thanks