Four Sisters and a Wedding - all the FLs are super overprotective of their brother
Backstreet Rookie - I haven't watched this all the way through, but I think she might fit.
Bromance - slightly and periodically (no jealous overprotectiveness though)
Search WWW - not to the point of being overprotective, by Scarlett can be a tad aggressive when it comes to defending Ji Hwan
GLs:
GAP - more on the possessive side of overprotective, but still possibly counts?
Notable Mentions:
Fast and Feel Love - not so much overprotective, as overly doting - to the point she protected/shielded him from a lot of things. The movie features her starting to let go of this behavior