I didn't think Rita was directing it at Jade because many artists have done Eurovision.
Rita was talking specifically about the Eurovision selection show on the BBC in 2009, which both she and Jade auditioned for. Rita walked away from the auditions and refused to take any further part. She basically inferred that she's glad she didn't go down that route because she's had more success by going her own way. Fair enough, but then she mentioned Splash!
and said that she'd never lower herself to do a show like that. As the only person who has appeared in both shows is Jade, it's blindingly obvious who Rita was referring to.
Rita seems to be a) assuming that she'd have won the Eurovision selection show if she hadn't walked away after her audition and b) assuming that now she's successful, she will always enjoy the same level of success. Silly girl.