hi tamirra,
if she isnt working at all she will be entitled to full benefits. these include housing benefit, council tax benefit, income support and family tax credits.
They deduct any maintenance from the income support but allow you to keep the first �10.00 of any you receive from the childs father. Family tax credit is �81.00 per week, per child and income support is �59.00 minus any maintenance. Housing benefit depends on the amount of rent to be paid, they assess the property and decide whether it is worth the rent being charged and award her accordingly. So long as she only has enough bedrooms that she needs, she should get the full amount. She will get full council tax benefit.
Once she starts working, provided she is doing the 16 hours she will still be entitled to an amount of the housing benefit and council tax benefit, plus working family tax credits and child tax credits. The DWP work it all out for her, the amount she earns, along with any child care she needs etc so she wont be worse off working, she will be better off.