Is this legal in SC?

So my husband is active duty Navy. We got stationed in SC around Dec of 08. We drove from Washington State all the way over here. Now we only had a day to pick a house, sign the lease and move in. We found out were expecting our 2nd baby and realize that moving on base was the best thing to do. So we get on the waiting list and we told our "landlord" that we will be moving out sometime in Aug-Sept. This was all in May. Anyways, I know in order to break the lease they will ask for 2 months of rent in advance. So im reading the lease all over again bcause we couldnt afford to break the lease then, and its stating " if the tenants break the lease, they will have to pay 2 months rent in advance, plus the momnths rent were staying there (so thats 3 months), and then on the other side its states, if the lease is being broken, the security depoist will be forfeited and will not be put towards damages to the house or last months rent. SOOOO I want to know if this is legal and if I can sue her for making us wait so long for something SHE DID ILLEGAL? (I am due Dec 15 and the longer I wait, the less I can do)

They can require the 2 month termination fee in addition to the month of rent for the last month you are there. This termination fee is not rent. It is a lump sum payment for permission to break the lease and being released from the obligation. It is standard in the industry.

They cannot make you waive or forfeit the deposit though. They have to account for that with an itemized list of damages and deductions from it and send you the list within 30 days after you vacate. If they fail to follow this (SC Code 27-40-410), you can sue them in small claims court for the deposit back and any penalties permitted by SC law. Some states allow a penalty of 2-3 x the deposit for wrongful withholding. (You'd have to read the statute to see if this is the case in SC.) Additionally, you are required to give a written notice to the LL of your intent to move out at least 30 days before the end date. That notice must specify an exact date to vacate (not sometime in Aug-Sept). If you fail to give this notice, you must also pay the rent for the notice period unless the unit is re-rented during that time. If it is re-rented, you will owe a prorated rent for all the days it was empty.