She’s a little bit funky. He’s a little bit rock ‘n’ roll. But they insist the combo will work.Jill Willis, former exec VP at Prince’s Paisley Park Enterprises, has opened Renaissance Management Inc., signing singer Donny Osmond as one of the first clients for the Minnesota-based firm. Willis also has signed Columbia Records artist Martika and Minneapolis-based singer-songwriter Robbin Julien — whom Willis is shopping for a deal — to management pacts. Willis, who spent three years charting the course for Prince’s interests alongside the entertainer’s manager Gilbert Davis, will open a Los Angeles office early next year, initially bringing on a staff publicist and executive assistant. “Many people don’t realize Donny had three top-15 singles,” Willis said. “As a pop and adult contemporary artist, he has a very loyal following.” Osmond is appearing in the Chicago production of the Andrew Lloyd Webber-Tim Rice tuner “Joseph and the Amazing Technicolor Dreamcoat.” Martika will release her next album in mid-1994.