Other mistake: To get revenge against the reds for chopping off his hat, Benny goes inside the house to use the computer to change the woman's lawn mower order. Benny never hits the 'ENTER' key to complete things. Things are completed when he steps on the 'SPACEBAR'. Same thing happens later when Benny is ordering a female flamingo.
Other mistake: When Juliet is getting ready to go after the orchid, she puts the second sock on (the black one). It fits her perfectly. There's no heel in this sock.
Other mistake: In the scene after Trybalt has cut off Bennie's hat, Gnomeo warns Trybalt of the wall. When the lawnmower hits the rock and he flies towards it, if you follow his trajectory, he should go over the wall. But in the next shot, he slams into it.
Other mistake: When Benny is going into the house to use the computer, he goes through the sewer pipes and ends up in the washing machine. First, the pipes would be too small for him to get through. Second, he wouldn't be able to get into the washing machine.
Answer: The pedal she was glued to was most likely destroyed from beneath her, which freed her.