You get some idea from my post.
http://www.immigrationboards.com/viewtopic.php?p=603815
Also FAQ
Q - Does my UK-born child qualify for british citizenship? Can I skip ILR for my child?
A - Child born in UK before either parent is granted settlement: There is no requirement for a non-travelling UK-born-child to be included in the settlement application of the parent (that the child is a dependant of). Immediately after a parent is granted settlement, their child is entitled to register for British citizenship (Section 1(3)), irrespective of child's immigration status. Whether the child has a passport or not, has valid (PBS or non-PBS) leave or not, or whether dependant leave will expire on the day you apply for settlement or 2 years down the line - is all immaterial. If you do not include the child in your settlement application and the child's current leave expires before he/she becomes entitled to be registered as British citizen, the overstay won't affect the child's entitlement for British citizenship, if/when you're granted ILR.
Child born in the UK after either parent has been granted settlement: Is a British citizen by birth.
Q - Do I need to include my UK-born minor child in my settlement application?
A - You may, if you wish to (example 1 below) or if your circumstances / plans may warrant so (example 2 below).
e.g. -
1. If you are uncertain of the success of your settlement application and your current leave is expected to expire while the settlement application is being considered, then you may choose to include the child as your dependant when applying for settlement - to have (false) peace of mind that your child may also have the same appeal status as you (I say false because a UK-born child does not need any leave to "remain" in the UK).
2. If you wish to travel abroad with the child soon after you receive settlement and do not have the time to apply for child's registration and British passport (and receive these documents) before you travel.