Qualifying period for ILR for Tier 1 General Dependants

Context:

I was granted HSMP on 05-09-2007, susiquently Tier 1 Genera on 05-09-2009. I will be eligible for the ILR on 05/09/2012.
My family (wife and children) entered the UK on 06/07/2010 as with permission to enter (visa) as Tier -1 General Mirgant's Dependants.
On 05/09/2012, they will also be eligible for ILR as by then, they would have spent 2 years and 2 months here in the UK.

Queries:

1. My wife wants to visit Pakistan for a period of 3 months. Is this 3 months absence from the UK going to effect her eigibility for ILR on 05/09/2012? I mean, to be eligible for the ILR on 05/09/2012 does she need to have continuousely lived in the UK for 2 years with no absence from the UK. What is the maximum period of time that can 'break the continuty of residence' for ILR in her case?
2. I have three kids, of with two will be over 18 on the 05/09/1992 when they will apply for ILR. They also want to visit Pakistan during the summer school holidays. Again, is this going to effect, somehow, their eligibility for the ILR on 05/09/2012.
3. For my wife and children to be able to apply for the ILR with me, do they need have been here for a minimum of two years by then


I will be thankful if references/links to the relvant sections of policy/law are provided

See also ILR - Dependant absence from UK.

Wife has to satisfy 319E. There are no minimum residential requirements for children (319J).

Thanks vinne. Yes I have already been through 319E. My question is: Is there any restriction on the period she is absent from the UK during qualifying two years, voilating which may disqualify her from applying for ILR with me.

I am talking about any kind of restriction similar to mine where I cannot live outside the UK for more than 90 days as a single trip or more than 180 days as a whole during the 5 years qualifying period, voilating which disqualifies me from the right of ILR on completion of 5 years and I may have to wait further for that. My question is: is there a similar restriction applying to my wife as well?

Any reference/links to relevant rules will be appriciated.