Funny how you lead with polio, which shows where your brainwashing comes from.
Polio is not an issue, mostly because the dirty, contaminated environment it flourished in has been cleaned up.
Before you sound ignorant, go look up if polio is a common or even optional given vaccine for children in California....
Then go look up the poor folks that got a "unfortunate" vaccine version and were guaranteed to die of cancer when they got older....
Now as to the rest.
Her kid could probably get measles, mumps, German measles, chickenpox and simply be sick for a week or two with each and recover fine. Those all have a greater than 99.99 percent survival rate.
You might find a lot of folks have had the whole batch of them plus some extra fun thrown in while they were kids & survived just fine with no lingering effects. Those same folks may also know hundreds of other children who had a similar experience and all are good and fine.
Let me guess, you are going to be preaching that everyone should be forced to get the Wuhan Virus "vaccine" along with their kids, personal choice be damned....