Was Lecy's scenes in "Springtime for David" and "Heart & Soul" (her last 2 episodes) pre-taped? Because I figured her hair at least would be a little longer but it was the same as it was in episodes like The White Sheep of the Family, Becky Howser MD, etc. and these episodes were like in the early/mid season 8.

She might have liked the length and kept it that way all the way through.

Also many actors have to keep their hair the same length because they film out of order, remember season three when Becky's hair was long then short then long.