New to broody hens and silkie mixes

[Basghettiii]

My Plymouth Rock hen named Jelly (the one in my profile picture actually) has decided to sit on a couple of my barnyard mix’s eggs. Jelly unfortunately has scoliosis, so I will not be allowing her to hatch out her own eggs, just because I don’t want the deformity to be passed down.
I am just wondering exactly what I need to do to help keep her as healthy as I can while she’s sitting. She’s just started sitting today, but she seems pretty determined, so I’m giving her a chance.
Is there anything specific I should feed her while she is sitting? I hear that I need to keep her weight up, and I usually give all of my girls high protein snacks like eggs and mealworms, along with more fatty snacks like corn and scratch. I’ve read that scratch is usually good for keeping their weight up, but I just want to make sure I’m taking good care of her while she tries to be a mother.
How often should she leave the nest? How long should she leave the nest at a time? I’ve read that she will leave about twice a day, and that she can leave for up to two hours at a time. I just want to confirm that my research makes sense.
On a lighter note, I would also enjoy some speculation about what the babies I could get might look like! I just think it’s fun to guess, and unlike the last time I hatched chickens, I have no idea what these ones might look like.
The girls who laid the eggs are a product of a red sex link and what appeared to be a red mix (he was the neighbour’s rooster, so we don’t really know what he is). Our rooster is a little black silkie. I’ll attach some pictures of parents here. These are all just possible parents, because some of their eggs look the same. I know the hens are all sisters, so genes should be somewhat similar.

These are the potential biological mothers (I might throw one of my BO’s eggs in there if Jelly decides to stick to being broody, and if she actually gives me an egg this week- she’s starting to molt)

This is my rooster

This is completely irrelevant to genetics, but here’s a picture of Jelly, my beloved broody

 

[Basghettiii]

This is also her first time even attempting to go broody, so I’m pretty excited! Trying not to get my hopes up too high, but it’s hard not to.

 

[schrody]

I have a silkie hen that I've let go broody and hatch chicks 3 times. I don't know exactly how long she leaves the nest, but its not long. Just long enough to go to the bathroom, eat food, drink water, and stretch her legs. She cannot be gone too long as she has to closely monitor the egg temperature and turn the eggs.

Idk what your chicks will look like. I have a silkie rooster too that is pure white. He's bred a brahma and a rhode island red, both offspring have non-fluffy feathers, predominantly white, with some light coloring from their mothers. So the half brahma is white with black spots on its back and the half rhode island red is white with some red/orange spots on its belly. Both have very minimal comb and they inheirited the black feet, black skin and extra toe of the silkie rooster except I think one of them only has an extra toe on only one of their feet, I'd have to check. These two are 22 weeks old now.

I did get a half brahma half silkie chick that had orange feet and light skin that I was super excited about but a hawk carried the poor thing away at about 8 weeks old.