Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Contact emergency services immediately if the child is in immediate danger, cannot be safely supervised, has a serious injury, has attempted suicide, or has a plan and immediate intent to harm themselves or someone else.
Seek prompt professional help if a child develops worsening depression or anxiety, stops attending school, runs away, uses substances, self-harms, or says they do not want to live.
Statements about suicide should be taken seriously.
Follow-up should be based on the child's specific medical, developmental, emotional, and safety needs.
Routine appointments may monitor growth, sleep, school progress, behavior, treatment response, and access to family services.
Young children and children with health or developmental concerns may need more frequent review.
The article also says
Care plans often work best when health professionals, mental health clinicians, schools, social workers, and safe caregivers share relevant information.
The child's privacy and local legal requirements should guide communication.
Every sign above is quoted from the sofidex article on Child neglect and emotional abuse. If you are not sure, err upward — it is always reasonable to be checked.