The versatile Newcastle United winger's temporary deal now runs until Saturday 4 May, including the npower Championship fixture at home to Blackburn Rovers.
The Northern Ireland international originally arrived at St. Andrew's at the start of last month on a short-term deal that ran until the Easter Monday visit of Wolverhampton Wanderers.
Now having made six appearances, including his first Blues goal during the 4-0 victory at Crystal Palace on Good Friday, Lee Clark has opted to keep the 21-year-old left-sider until the end of the season.
Clark told bcfc.com: "We think Shane’s a terrific little player and he’s a great kid; we’re delighted that we’ll have him for the rest of the season. I think the deal has benefited us, Newcastle and Shane. He’s brought quality, tenacity, speed and energy and he puts in quality deliveries. You’ve also got to remember just how young he is as well."