Question California, U.S., Federal Naturalization Records

I am coming across petitions for naturalization whereby the only dates shown are arrival, marriage (if applicable) and birth dates of petitioners plus any children. But the dates for the children are after arrival date. Therefore, the petition entry shows before the child's birth entry. webtrees flags the naturalization entry as it's before birth.

Arrival: 01 Jan 1955 California
Married: 01 Jan 1950 Ontario, Canada
Child: born 01 Jan 1959 California

(I may have asked this before but failed to find in Search)

How relevant exactly is the naturalisation for such a child?
I thought a child born on American soil was automatically American citizen.

Is it possible the whole process takes years? Then the date of petition is not the date granted. Meanwhile children can be born.
You can consider date approximations (bef / aft) or ranges.

I do not see a real bug.
may be the event should not be attached to the child.
the parents did.