Step 4: As you connect with your sorrow, you connect with younger parts of you, parts of you that didn't know what to do with those feelings. (mindbodygreen.com)
I think thats a personal preference — I think the too young part is more crucial because they should be legal age. (blog.seekingarrangement.com)
Wednesday Increasing self - compassion by cultivating compassion for younger parts of the personality: Learning to ask, «How did this part help me to survive? (cape.org)