A quick observation : in the OP's example, the statement "my parent is my mother" is true but not complete.
A false statement would be "my ONLY parent is my mother" - but that was not stated nor does the actually stated form imply that "my parent is my father" cannot also be true as one person (conventionally) has either two parents or is a clone -case in which the team of scientists and the "parent" organisms can be seen as "mother(s)" (?).
Anyway, the pedantic thing to call that could be "assimetry by omission" in which one would adress elements of the subclass "mother/father" in relation to the descriptor in the superclass "parents" that includes it. Generalization by omission, or simply stating parts of complex truths without implying completitude (not a lie by omission), are weaker forms. In extremis there is nothing wrong with the example given from a strictly logical point of view " my mother is my parent" =true, but the other part of the truth " people (usually) have two parents" = also true does not change the first conclusion.