Inner children can be considered as guardian of certain Parts. (Be careful not to confuse Inner children with an Inner Child. The naming of inner children came first before the concept of the Inner Child was fully understood and incorporated into ART.)
When encountering inner children, think of yourself as speaking to the gatekeeper who will determine whether you may have access to the parts in their care so you may heal them.
Ask if the inner children are safe to heal.
If the answer is no, make them safe by healing the relevant Aspect(s)
Once they are safe to heal, ask if their parts are ready to integrate. Integrate parts as normal, releasing stuck energies if needed.