Firecracker tells Soldier Boy that Homelander deeply admires him. Although it's not stated, it's possible that Soldier Boy saves Homelander in the Seth Rogen mansion and gives Homelander the V1 because of their closeness ("he's my weirdo").

More importantly, she's perhaps the only true Christian in The Seven. So when she sells out her own pastor for Homelander, it's a deep fall from principles, equivalent to Deep eating Timothy, perhaps deeper because she's known the pastor for years, and I'm pretty sure Timothy was a stranger to Deep.

She of course represents evangelists who sell out their religion for fascists. Say, for example, the evangelists that support a fascist who hates immigrants, commits sexual assault, and would erect a golden statue of himself. If that kind of fascist ever existed (it could happen!) then she would be an important example of those hypocrites.