analogy
brother mother
fly ?
Mother fly? Female fly??
If brother came from mother, then one could say that fly came from larva...
An analogy for "fly" in relation to "brother" and "mother" could be "bird." Just as a brother and mother are both part of a family, a bird is another example of a living creature.
In order to find an analogy to the pair "brother:mother," we need to identify the relationship between the two words. In this case, the relationship is that "brother" is a type of "mother." Now we can use this relationship to find the missing analogy.
For example, if "brother" is a type of "mother," then we need to find a word that is a type of "fly." One analogy that fits this relationship is "butterfly." A butterfly is a type of fly, just as a brother is a type of mother.
Therefore, the missing analogy to the pair "brother:mother" is "fly:butterfly."