I reported my suspicions to ebay and finally it looks like ebay have taken action. All the seller's current auctions have been taken down (at least 8). I believe my suspicions were correct. After the seller's six auctions ended (won by zero feedback bidders), she relisted all of them again. That's when I sent the seller a message voicing my concerns about possible shill bidding and strangely enough (after my communication with her) not a single zero feedback bidder bid on the relisted items, so there were no bidders up until the time ebay brought down all the auctions.
I hope this seller has learnt her lesson and plays fair in future. I'd hate to see anyone else overcharged for an item due to shill bidding. Greed is so ugly.
Happy shopping ladies!