The real question which needs to be answered is where do institutions need to draw the line for equal opportunity? Do institutional services need to be a zero sum game? Can we offer the same services to everyone — education, healthcare, UBI — where providing services to certain individuals is not at the expense of other individuals?
Don't give them any ideas!
Could it ever begin before conception? Could it ever begin before birth? At 6 months of age? At 1, 2, or 3 years of age? Is it 100% “on them” at 12, 16, 18, or 21?
That really depends on what you are referring to by "our society." If you're talking about the US, many would dispute that characterization.
It's a subjective, unquantified statement. It cannot possibly be called a fact.
In any case the proof is in the pudding: children in the US who are born poor are highly likely to die poor, and we are significantly worse in that respect than other Western countries.