Don’t use the parent/child terminology when discussing inheritance relations.
The parent/child terminology is appropriate when discussing “has-a” relations. (A parent has a child, and a child has a parent.) In other words, this
/homeis the parent directory of
abcdnode is a child of the
abcnode in a trie”
is perfectly fine.
An inheritance relation on the other hand, is an “is-a” relation, as in
A cat is an animal
It does’t make sense to say that an animal is the parent of a cat or that a cat is a child of an animal (at least not when there’s only one cat around). A parent and a child doesn’t have an is a relation with each other.
In the case of inheritance there’s always a better terminology: Superclass and subclass. So, instead of saying for instance
Animal is the parent of Cat
Animal is the superclass of Cat