Pugh has served on the board since 2001 but resigned her seat Monday amid intense scrutiny over the total $500,000 the medical system has said it spent to purchase 100,000 “Healthy Holly” and “Healthy Herbie” books from Pugh beginning in 2011 — the same year she established her company. Pugh and UMMS have said the deal was struck to distribute the books to students in the Baltimore public school district, which it did not request and still has thousands of copies sitting in boxes in a warehouse.