Workplace etiquette question.

It's 1/15. I submitted my November receipts (grand total of 2) in December to my admin for reimbursement. I see online that she hasn't even started my November expense report. I won't even get into the December one, which had all the receipts turned in electronically before the middle of the month.

Is there some way to politely light the fire here? I walked in and saw another co-worker giving her the 3rd degree, we'll see if something happens, but this is like the 3 rd time in the last year its taken for ever to get paid as a result of her taking her time. And I can tell from all the printed out Kohl's coupons and "Hey let me find you a coupon for X activity" stuff that she's not working 100% of the time. How do I handle this?