If her tax return was rejected then she can log in to her account and add the Form 1099-INT.
If her tax return has already been accepted by the IRS then she'll need to wait until she has received her refund and file an amended return.
She can prepare an amended return in TurboTax but she'll need to mail the return. E-file is not available for this type of return. Please follow the directions below to prepare an amended return.
https://ttlc.intuit.com/replies/3288565
