My rescue chickens - Mamma and 3 babies

Describe 'My rescue chickens - Mamma and 3 babies' here

  Any buddy have an idea what type of chickens these are?  I rescued them from a neighbor who inadvertently ended up with the mother who soon layed and hatched 3 chicks.  They were in deplorable living conditions and I couldn't leave them there.  Problem is Mamma doesn't get along with my 7 hens (see them below helping my husband).  Mom and chicks roost in the trees at night (she originally staged a "coo" and took over the coop not letting my girls on their roosts.  But somehow the power shifted and my girls are back where they belong at night and the 4 of them have taken to the trees.  They are getting pretty social, coming running to me when I come out back (they've learned quickly I always have treats!).

It's been fun watching them grow, but I'd like to find them a separate home.  Mom attacks my girls if they get a little close.  Silly them, they forget she will when I'm giving them all oatmeal.

Also, can any one tell me how soon a mother starts laying eggs after hatching chicks?  I have an acre backyard and am wondering if I need to start searching for eggs.

Another question...when will I know if any of the chicks are roosters?  (I don't want roosters!)

The girls love helping my husband dig!