Short answer
Usually yes, eligible family members can be included in a subclass 186 application, but they need to meet the family-member and visa criteria that apply to them.
Family members are generally dealt with as members of the family unit. Some family members may be included in the combined application, and limited later or separate applications may be possible for newborn children, partners or dependent children.
Family members still need to meet the relevant relationship, health, character and other visa criteria. In some situations, the timing and way the family member is added can affect whether the visa can be approved.