since i got out have gotting married and have three girls. i am leaving for basic in aug and
was wanting to know when i finish and get assigned to a unit my wife wants to stay here because we just bought our home and we have 2 girls in school and she dont wont to up and move them. will be able to BAH if they stay here and i go to and unit.

From the time you enlist until you arrive at your first Permanent Duty Station (PDS) you will get the BAH rate for your dependents location. When you get to your 1st PDS the BAH rate will change to that location, no matter where the Dependents are located.

Example:
Dependents are located in North Dakota.
Basic and AIT at Ft Knox - BAH is at the North Dakota Rate.
Further training at Ft Jackson - BAH is at the North Dakota Rate.
Arrive at First Permanent Duty Station Ft Drum - BAH at the Ft Drum Rate.

If you are assigned overseas this may change. That is something to talk to the local finance office about if it happens.

Hope this helps