"Changeling"

I guess my one lingering question is this: why wasn't there anyone besides a dentist and schoolteacher (as if they weren't enough) who could confirm that this wasn't really her son? If this hard-to-believe facet actually runs true with historical events, then Changeling is quite a powerful commentary on the times, especially in terms of female disempowerment and political corruption. But I suppose I'm always skeptical when it comes to Hollywood depicting "real life" events.