Are all vegetarians anemic and brittle-boned? can you share some sources?

May be: Vegetarians are at risk of certain vitamin deficiencies. A common cause of anemia in vegetarian is B12 deficient. Symptoms could be - related to anemia, fatigue, numbness and certain neurological symptoms. Supplements are recommended.

No: Getting enough iron and calcium in a vegetarian diet is often difficult, but if you'll get with a vegetarian-friendly evidence-based physician or dietician who can guide you, you should be fine. Especially, if you're going to force your children to be vegetarians (and I advise against this), be VERY sure they're getting supplemented thoroughly.