Give her a bit of time. Right now the new girls are interlopers - and a good hen just cannot trust them I think once she knows the new girls are not going anywhere, she will become curious about them.
Yippy for the new girls
You might (if you have not already) - join the Southern CA thread: https://www.backyardchickens.com/forum/viewtopic.php?id=161
See if there is anyone near you who might have some birds
I understand about the quarantine. It also give you and the new birds time to get to know each...
In the garden for Penny during the day would work - as long as they do not come in contact with each other.
I do not have any Marans, I have one BR. She joined my flock as an adult and is a bit pushy. My flock is mostly orpington blood (even my EEs) and they are really laid back.
For the...
Can you get two to add?
If it was me. I would try to find teenagers or close to POL (point of lay) chickens if you can. (you have a quarantine area, if not then I would get a couple chicks - but still you need brooder area)
If you get two, they will be friends with each other. You will...