No sex for 6 weeks after delivering a baby, but what about just having orgasms?

Go for it: Orgasms via any method other than intercourse and intra vaginal "toys" which can cause a post-partum fever if not clean, are "releasing" and harmless.

Unless you had traum: Unless you had a very traumatic delivery, an ograsm should not cause any physical damage after child birth. If you had a c-section, then the contractions associated with an orgasm might be painful due to the repaired uterus. Even then, it is not likely going to cause damage to have an orgasm.