I have a chart very similar, but has a few conflicting genders! It's been right for my first two, just gotta see if it's right this time. It was also right for my sisters 7 kids, my other sisters 4 kids, my SIL's 2 kids, and about 95% of my friends!
I've known my chart to be incorrect about 5 times I think, and I use it on everyone!
To be fair it has a 50/50 chance of being right! I could guess for you all and probably get it right in quite a few cases!