We are supposed to close on 9/25/14 now seller wants to stay on house 2-3 more days because she has no where to go.what should we do?

This is not an uncommon situation.  You are right to be leary because allowing the seller to remain could give rise to a leasehold/tenant interest in the property by the seller.  If you have the ability to not move in on the closing date, you can agree to allow the seller to remain for a short time.  You'll want a simple written agreement addressing things such as a fair daily rental amount, insurance coverage, the deadline for the seller to turn over the house and what happens if the seller does not comply with the next move out date.  If the seller refuses to leave (usually because their new residence plans fall through) they could claim they are a tenant and force you to go through a landlord/tenant process, which has special rules that will make it difficult to get the seller out quickly.  The agreement should set forth clearly that it does not create a landlord/tenant situation and that it is not governed by tenancy laws and rules.  It should include severe financial penalties in the event the seller does not leave in time.  You should hold a substantial amount of money is escrow from the closing to ensure that the seller does leave on time and, if not, there's a pool of money to pay you damages.  Even if the seller remains after the closing date you should expect to receive keys to your own house at the closing table.