Prince wouldn't be pissed at Justin Timberlake for using his image and voice during the Super Bowl halftime show, at least according to Prince's sister ... who wants JT's haters to back off.
Tyka Nelson tells TMZ ... she was pleasantly surprised by Timberlake's performance, and even enjoyed his controversial Prince tribute. She and the rest of Prince's family knew he was planning to sing, "I Would Die 4 U," but says they weren't aware he was doing the video projection.
As for the backlash -- Tyka says everyone has their own idea of what Prince would have wanted .