Millie.
Millie was always going to be special. Not super awesome girl boss special, but out of the ordinary special. She was always meant to be strong and resilient, and to 'have a way about her.'
Her helping Tiarraluna with Jack was something that came right from the start, even back when Cable and Tiarraluna were supposed to arrive with him ahorseback and her in an ordinary wagon. (before I realized that Tiarraluna couldn't drive one)
The notion that she could pick FoeSmite up without injury came next. In my mind, it had to do with how completely innocent and guileless she was, and how appreciative she would be once she found out what the staff's nature was. The clay pot she puts FoeSmite's butt into is filled with water and fertilizer, by the way. I may have left its contents out of the finished draft. Renee could always sense that Millie wasn't anyone she wanted to harm.
The idea that Millie could converse with spirits came fairly recently, after I'd established that everyone was gifted in some manner, but that, in the vast majority, the gift was so weak that it was all but undetectable.
While Millie has a gift, it's pretty weak, and of limited value, unless used very cleverly. She has no real ability to control mana, she has no extra special stats, no above normal power. She can see and hear spirits. That's it. At least, so far.
Thus far in her short life, she's been throttling this meager gift. What happens when she begins to exercise it? Will it grow? One thing is sure, she's developed a bond with FoeSmite, albeit nowhere near as strong as Jack's.
This tale has been pilfered from Royal Road. If found on Amazon, kindly file a report.
While she cannot, and will never be able to wield FoeSmite directly, I wouldn't want to be the guy who tried to mess with her if the staff is anywhere near. We've already seen that Renee has some limited ability to move on her own.
Juniper.
Juniper is pretty new as a character, truthfully. Oh, she's been a story factor from early on, but only in a vague, "younger sister tied up in the corner to be sold" sort of way.
As is my wont, I gave her a name, set her loose, and let her run with it, forming her personality on the fly. She may be acting a little older than her age, but not, I think, much. Kids on these worlds grow up pretty fast. She's got that whole, "what'll my friends think about my crazy sister!?" vibe, and she's not bashful about laying into Millie about it.
Leaving aside, of course, that they lived on a farm out in the middle of nowhere in a higher ranked zone, and didn't see anybody but each other more than once or twice a year.
The family
We know the father's name was Johannes. I never gave the mother a name. Johannes got one because of the amber life stone, and the part it would play in the future. The mother didn't drop one, so there was no real reason for her to have a name, and I'm not quite autistic enough to name everybody with even the briefest appearance. Nearly, but not quite. Alright, apparently I am autistic enough. Their mother's name was Sellia, per Millie's reflection in chapter 42.
They were cow farmers. Dairy. Made cheese, mostly. The girls' father, Johannes, got lots of practice with his scythe fighting off the wild beasts and lesser monsters once the supply of adventurers dried up and the area grew more dangerous. Which was probably how he managed to score a meaningful hit on a very surprised Lar. The aftermaths of these thwarted beast and monster attacks were where Millie learned her doctoring skills.
They finally ran out of cattle, and with little else to hold them, they abandoned their farm to seek safer environs. Which was what they were doing on the road when Lar, Stetz, and Dimo, along with a couple of the other bandits, jumped them.