mean in this sentence?

Annie had interpreted for her mother at the pharmacy, the bank, and the doctor's office, but never at a parent-teacher conference for her little brother, Andy. She sat between her mother and Mr. Garrison at a desk built for third graders, her knees almost touching her chin.

"Andy is a bright kid," Mr. Garrison began, and Annie put it into Vietnamese. Her mother smiled and nodded.

"His reading has improved a lot this year. He's moved up two levels." Annie translated that too, and her mother's smile grew.

Then Mr. Garrison turned a page in his folder. "What we need to work on is his behavior during group work. He talks over the other students, and twice this month he refused to let anyone else hold the materials. He's been sent to the hallway to calm down three times."

Annie hesitated. She looked at her mother's hopeful face and thought about the long drive home, about how quiet her mother got when she was disappointed. "He says Andy sometimes talks too much in groups," she said in Vietnamese. "He's working on it."

Her mother nodded slowly. Mr. Garrison went on to explain a chart he wanted Andy to fill out each day, and Annie translated every word of it carefully, as if being exact now could make up for what she had left out.

When they reached the car, her mother didn't start the engine right away. She sat with both hands on the wheel.

"Three times in the hallway," she said in Vietnamese. "That is not 'sometimes talks too much.'"

Annie's face went hot. "You understood?"

"I understand more English than I speak," her mother said. "And I understand my daughter. You wanted to protect me. But I can't help Andy with a problem I don't know about."

Annie stared at the dashboard. "I'm sorry."

Her mother started the car. "Next time," she said, "tell me everything. Let me decide what is too heavy to carry."