In the state of Georgia is is Legal for a landlord to do a inspection before a tenant move out of it not in the rental agreement?

Become informed. Read your state’s landlord and tenant act.

The landlord can inspect the house whenever they want, with proper notice (usually about 24 hours), so sure its legal. If I were the renter I would demand a 2nd walk thru right after they move out, just so there are probably no surprises when the deposit it returned.

The lease may or may not have specific clauses concerning entry, however, it is legal in all states for landlords to inspect property with appropriate notice. The notice period is usually 24-48 hours prior to the inspection. Inspections can be conducted for anything for move outs, to pest control, to routine mechanical checks for the HVAC. A landlord who inspects is a landlord who is active in the management of the property and wants to make sure it's properly maintained. 

A move out inspection is pretty common and doing so prior to move out allows the landlord to figure out in advance what repairs need to be made. They can use this information to schedule a carpet replacement, or to determine whether additional cleaning is needed. It's a VERY common business practice and it's one that tenants can actually benefit from. This is a great time to ask about move out expectations, to see if there's additional things that you need to fix/clean prior to move out, and to get a sense of what charges (if any) will come out of your deposit. 

It's also worth figuring out what the deposit return period is in your area. In my area, a landlord has up to thirty days to conduct a move out inspection and assess damages. Not everyone gets their deposit back on move out day and, if they do, the inspection needs to be conducted before they move out. You can't have it both ways.

Inspections and walk throughs are never in a lease.  They are not part of a lease agreement.  The landlord has the right to both and if he wants to inspect before she moves out, he has that right.  Random inspections are common in many places.

Makes sense, so he can warn her of anything wrong while she has time to fix it, then again when she adtually moves

It's legal in all states for a landlord to inspect his or her property--the amount of time the LL has give a tenant for inspection varies, though. But a LL is permitted to inspect the property whether or not it's in the rental agreement. When a tenant moves out, or has given notice, the LL may arrange for an inspection. There's nothing wrong with that. It's to the tenant's advantage if the LL wants to come earlier than is necessary--she will have time to do any needed repairs or cleaning that she needs to do before moving. Unless it states in the lease that the LL is NOT PERMITTED to enter the property except in case of emergency, there really isn't a problem here. As long as she and the LL agree to a mutually beneficial time.

It is legal for the LL to inspect their property at any time they wish, given proper notice.  

Not only legal, its reasonable and a tenant should appreciate it.

Landlords have the right to do routine inspections while the tenant is still occupying the unit. They do not have to put something in the lease in order to have permission to inspect their own property.

Inspections should not be excessive and should not be to judge the cleanliness of the home, only to look for damage or worn out items like dripping faucets.

Also the inspection conducted 2 months before moving out would not serve as a final move-out inspection.

Bottom line is that if the landlord has given proper notice there is nothing the tenant can do to stop the landlord from entering the home to conduct a routine inspection.

It's in the landlord's best interest to inspect when the place is empty.  There is nothing illegal about an earlier inspection, but the tenant should make sure they either get sign-off in writing at that time or they insist on another inspection once moved out.

As always, and more important in this case, take video and pictures of every part of the house and keep it just in case the landlord claims something after the fact.