I think Krista's can just happen out of order. I have never once met Bob. Not sure how or why. Totally ignored the Netorare settings on the Q-menu for two playthroughs then enabled it on my third to see what happened. Nothing. Unless selecting "No" on the "Disable Netorare" prompt actually means, "No, I don't want to enable that." There are also scenes in the gallery that have art...and maybe dialogue, but aren't in the game yet and need the gallery unlock button to be viewed.
To answer your question, Elena can get pregnant. Full belly, pouty face, and pregnant sex. The gallery shows Susan getting pregnant but I didn't get that scene naturally. The two sisters in the starting village state directly that they're pregnant after the pure-route threeway but don't actually get any rounder. There's an elf-milf that I haven't actually been able to progress with normally--I'm assuming I need to boot Krista from the party first, but never got around to trying that. Anyway, she and Krista can be "impregnated" but I don't think there's pregnant art of them.
Shit's whack, yo. But despite my annoyance at the typos, the partially-broken gallery, Krista's husband making no fucking sense as a character, the lack of clear progression, and the abundance of game-breaking fuckery like the war with the bandits sometimes giving you less than a day to make preparations...the thing that annoys me the most...
Is the fucking pig that won't leave my inventory. Fuck Serana and her free daily stat-ups, it's not worth it.