The interest IS currently accruing, so every dollar you have ‘out’ is accruing interest under the terms of that loan. You aren’t paying the interest as it accrues right now, but it’s still building up. You will benefit it you pay it off now, but like kelsmom says, if you can reverse the transaction right now, do that and the origination fee will also be refunded to you. OR, if you need the money you already borrowed, just cancel the January disbursement and use the $3500 scholarship to pay the Jan expenses. Interest is not accruing on the $4000 your grandmother is scheduled to borrow in January and won’t be until it is disbursed.
Interest on Plus loans and the unsubsidized Stafford loans begins immediately. The PAYMENTS are deferred for the grace period, but the interest IS accruing.