Do you have non-ACA insurance? One explanation for why your costs are so much higher than the national average is that you're on a non-complying plan (you can also still buy plans that will exclude preexisting conditions --- they just can't be sold on the ACA marketplace). I'm pretty confident KFF isn't making these numbers up.
As for your second question, one easy response is that prospective parents in other health care systems aren't paying less (with everything factored in) but rather differently: that people making your $119k "true" poverty rate in Europe tend to be taxed at their top marginal rate, which is substantially higher than ours (in fact, in a lot of places in Europe, a Chicago Public School teacher would also be paying the top marginal rate).
A thing worth pointing out is that while the system we have is especially punishing on the uninsured, it's actually not that bad a deal for the insured, demographically/actuarially speaking. That's because being insured definitionally puts you in the cohort that excludes Medicaid-eligible poor/working class people and fixed-income seniors. If you move the typical household from that cohort to the UK, they're likely to be worse off. In surveys, insured families tend to be satisfied with their insurance, which is why taking existing health insurance off the table is such a third rail in American health policy.
Anyways, unless you personally are responsible for keeping our population above replacement level (which sounds exhausting), your numbers just aren't probative for the cost of bringing new citizens online. Other numbers might be!
