In the printer’s manuscript, Oliver Cowdery originally wrote “the people of God”; then virtually immediately he replaced people with children (the level of ink flow for the supralinear correction is unchanged). In the original manuscript, only the final n (of children, presumably) is extant, but that one letter shows that 𝓞 did not read people. Nor would there have been any motivation for Oliver to have emended “the people of God” in 𝓟 to “the children of God”. Elsewhere in the text there are nine occurrences of “the people of God” and four of “the children of God”, so in each instance we follow the earliest textual sources.
Summary: Maintain in Alma 30:42 the occurrence of “the children of God”, the apparent reading in 𝓞 and the corrected reading in 𝓟.