What does 'Brambles' mean here?

Here's a scene from the movie 'Lady Bird':

Miguel and Shelly eat cereal. Larry reads the paper. Marion makes Lady Bird’s breakfast and her lunch.

LADY BIRD Why can’t I just make the eggs?

MARION Because you take too long and make a big mess and then I have to clean it up.

SHELLY (small voice) Eggs aren’t good for the environment, anyway.

LADY BIRD (too loud) WHAT?

MIGUEL You heard her.

MARION (placing the eggs) Here, eat quickly, PLEASE.

LARRY (re: paper) Look at all these pictures. Every newspaper looks like USA Today.

MIGUEL Shelly and I are trying to be vegan. Hence the soy milk.

LADY BIRD You wear leather jackets.

SHELLY They’re vintage. It doesn’t support the industry.

LADY BIRD (poking at the eggs) They aren’t done, there’s white stuff.

SHELLY You know how you love Brambles? Pigs are smarter than him even.

LADY BIRD I never thought Brambles was a GENIUS okay?

In the last two line, Shelly and Lady Bird are talking about "Brambles".

Could someone tell me what "Brambles" is in this context?