Liz put the pressure on Julia to step up her game.
Liz was visibly annoyed after Julia lost a puzzle-building HoH competition, and she let her sister know exactly how she felt. After throwing Becky under the bus—apparently, the twins couldn't believe that the Colorado girl could hold her own in a battle of wits—Liz told her twin that she needed to step up her game and keep them both off the block.
Feeling overwhelmed, Julia said her sister was putting far too much pressure on her. Later, Liz admitted that she, too, felt stressed because she's fighting for two.
While the sisters have had a few small squabbles, they both are dedicated to protecting each other. After all, they're one another's strongest allies.