Would a person with Anorexia nervosa be more likely to break a bone than a regular person?
Let's think step by step below.
yes
People with Anorexia Nervosa restrict food and as a result lack essential nutrients.

Many people with Anorexia Nervosa, are at high risk for osteoporosis(and to a lesser extent bulimia nervosa) will have low bone density and consequently reduced bone strength.

People with Anorexia Nervosa, are at high risk for osteoporosis.

.

Thus, the answer is yes