I hope they agree when she comes out that you can stay together as a family..you will need a lot of support yourself because you will then become a main carer for the DC's and your DW. Thats why i asked if you work.
It will be tremendous pressure, you will need all the support you can get. Please don't forget to ask for an adult social worker as well...they will support you, and are not IMO as 'frightening' or seemingly 'unsupportive' towards parents as CP social workers, whose job it is to see that the children are safe, so they won't engage with you much beyond that, which i believe is a failing of the social services.
Supporting the parent often has the added bonus that they are more able to care for their children. A fact that child protection often overlook or blatantly ignore In MY Personal Experience.
Hopefully you get good old fashioned SW's that know this and will go all out to help your family.
A word of warning.
You will be offered respite. Take it if you wish, for a weekend or such, but i personally would not. DO NOT accept any offers of placing the DC's into temporary accommodation, a 'back door way' of removing most kids into care. Once they are in, it might be hard to get them back out.
NEVER say you can't cope. Allow THEM to offer the support, don't specifically ask for it, make out you can cope without their intervention, and any support they offer you consider a bonus for the kids..
In other words..Don't appear unable to cope or needy.
The rest should be a breeze. I am not scaremongering. I have been through this personally...and learnt a hard lesson.
Good luck and well done for keeping your family together and going all out to care for your kids