I presume you're talking about Lynda Woodruff? She's a character created by Swedish singer Sarah Dawn Finer (the one who sang the ABBA cover later in the show).
The original sketch with her is from Melodifestivalen 2012, and that made fun of Azerbaijan hosting and her pretending to be a really dumb Essex girl who was doing things like not being able to pronounce Azer-aza-Aserba.. Baku (that sort of thing). That original sketch was reasonably good, the ones since in other Swedish Eurovision projects have worn the joke a bit thin and have nothing on the original.
The interval act with Petra was great - it's so good to see a host who's actually funny and entertaining, Sweden did really put on a great show.