There is _some_ truth to what you're saying, but only a bit.
> the government decides how much to spend on care
This is true, there are limits to what the government will pay. The NHS, which isn't far from the gold-standard for socialized medical care, does indeed not stock some drugs that are deemed too expensive. Here's a good write-up of QALY's and the NHS:
https://www.bbc.com/news/health-28983924
If your child had been born with spina bifida in the UK, all treatment would have been free. This treatment would include (from 2018) pre-natal surgery, post-natal surgery, physiotherapy for life, occupational therapy for life, special educational needs, mobility aids for life, and all manner of treatment for association problems, including kidney treatment for life[0]. Here's a summary of the NHS treatment for it:
https://www.nhs.uk/conditions/spina-bifida/treatment/
> In a country with socialized medicine they’d probably have just let her die
How much research did you actually do on this point? I'm always amazed by how much Americans suck up the death panels bullshit. If a fraction of what all y'all believe about socialized medicine was true, then free medical care wouldn't be free at point of use in literally every other civilized country on the planet.
That you are willing to believe all the world except Americans are idiots for the way we have our healthcare setup beggars belief, and reflects poorly.