The player will additionally be available for selection for Saturday’s Buildbase FA Trophy Semi-Final first leg tie at Brackley Town.
The 20-year-old is an attacking full-back and known for his abilities playing further up the park.
A speedy and powerful player, has also added goalscoring to his game.
Alongside representing the Royals academy sides, the young defender has also represented his country, Scotland, at youth level; he was initially part of the Scottish contingent that made the UEFA Under-17s Championship semi-finals in May 2014 and has since gone on to play for the U21s North of the border.
Sheppard spent time out on loan in 2016/17, impressing at Dagenham & Redbridge where he scored twice in ten appearances in the National League.