The 19-year-old scored the winner at Huddersfield on Saturday then capped of a supebr few days for The Lions by setting up Gary Alexander's winner last night.
The deal means the youngster will remain at the end Den until the end of the season.
"We've agreed to extend James's loan by another two months," manager Kenny Jackett told the club's official website. "It's actually 93 days in total, including his current spell which was due to expire after the Leicester City match on Saturday. That would take him up to, and including, the Play-Off semi-final.
"He's done very well for us but you don't want to start building people up to soon because, even though he's had a good few games for us, that doesn't make a career.
"It works for everyone because Reading have a player who is gaining experience, James is getting games under his belt, and we're seeing a player that's really contributing to our cause."