Package Lost or Just A Scam

Couple weeks ago i sold an item in eBay worth $57.00 and i mailed the item on the next day after i got the payment from the buyer. Now two days after i mailed the package the buyer email me that she didn't receive the package yet, so i told her to wait 3-10 days from the day i mailed the item co's its a parcel post and it doesn't have tracking number. You have to pay to have tracking number and i didn't get one co's the buyer didn't ask me either. Almost every other day she keeps emailing me that she didn't get the package so i email her a copy of the receipt showing i did mail the package on her address. Until now she said she still didn't get the package so she file a claim for refund on paypal. I didn't give her the refund yet co's I'm not sure if she's telling me the truth or what. I email her that if she didn't get the package it should come back to the sender because i can't imagine a 9lbs. package lost. I been mailing lots of stuff didn't happen to be lost even if how small they are. For now I'm just waiting for paypal whats the decision gonna be. Boy if i have to refund it and i don't get my item back its gonna be a big lost on me. I can't even withdraw my money in paypal because of that case. Bummer!!! I'm trying to make money now this what gonna happen. Oh! life just ups and down.