Red Legged Partridge with chicks in garden

Hello! 

A Red Legged Partridge pottered into our garden this afternoon with around twelve chicks. She's been sitting on them under a bush since then. I wonder if anyone could answer a few questions I have please?

- How long do you think she'll stay there? We have a dog and I'm considering asking a family member to have him until the chicks have gone if they'll be with us for a while.

- Is there anything I could/should be leaving out for them? 

- Is there anything I can do to protect them from the neighbour's cat?! Grimacing 

Thanks so much in advance for any advice!

Lucy