In most cases all that means is the mother reported that she was breast feeding after the vaccination.
There's no determination that the vaccine traveled to nor affected the infant.
And if you look at the AEs on the 41 you'll see primarily minor issues which aren't necessarily tied to the shot.
As is typical for these anti vax articles it's based on a misrepresentation of Adverse Event data.
I looked at the AES and they did not seem minor to me.
There were 6 severe adverse events too, that’s 3.4%.
Hospitalization rates for infants (0-4) for Covid was only .06% at its highest, according to the CDC. https://www.cdc.gov/mmwr/volumes/71/wr/mm7111e2.htm
IF anyone is playing down the adverse events, it’s you.