Arnold owns and manages Coldwell Banker Apex, which has over 1,000 agents who do over $4.4 billion in annual sales. In 1982, she joined the company her mother founded in 1973, and her son and his wife now work in the firm as well. The Texas-based firm now operates 22 offices serving Louisiana and Texas. The company is the largest women-owned Coldwell Banker franchise in the U.S. In 2019, Arnold was the first woman to chair Coldwell Banker’s Multi-Office Brokers group.