personally I wouldnt give fuck all to anyone in my family except maybe my parents, and if the money wasnt self-earned like in this case, I'd probably make them believe it came from an anonymous benefittor. theyd get like 1m. Id use the remaining 9m on myself, as you ought to.
also, the point is not who you choose, the point is, word will go around you are giving away money and this will lead to a barrage of beggors arriving at your doorstep from family, friends, people in the community and everyone you know and once knew. do you really want that kinda shit? discretion is advised.
many popular charities are doing more harm than good or worse, are scams. and I'd rather not give my comparatively small fortune away to charities with social inequality being this rampant, especially not as social tension is expected to increase dramatically over the next 30 years due to climate change induced stress factors.
Chances are it's not gonna make a change whatsoever on the scale of things. I'd put local things like the dog shelter in your city or volunteering psychologists or whatever as the exception. But overall, charities are a no-go. They are ran like businesses nowadays and it's fucking awful. They are also used as a tool for ultra wealthy and corporations to appear socially involved and caring, which they are absolutely fucking not. Large amounts of money bring out the worst in people, so chances are your million dollar donations would go to waste, into the pockets of a scam artist (because either the charity itself is ran by one or because the cahrity itself got defrauded), go into the pockets of a greedy charity CEO (yes, many charity CEOs take salaries 120k upwards), fund terrorism or cement social inequality like in africa, where global charity actually prevents the local economy from ever prospering.