Refunds do not just happen either she opens a not received case, or you originate a Full refund.

She is now out of time, for opening a case, but you can refund up to 90 days.

Without knowing why she thinks she has had partial refunds, in my opinion you could lose out by posting now. She could go to her payment provider and claim not received and get a full refund that way, as well as the item if you now posted.