This isn't a question but those of you who are having troubles with brother:mother::fly: the answer is spry. It's a word but I didn't know it was a word until my parents gave me the answer LOL but this was a very handy site considering the fact I had the same one for the week!
Thank you for sharing the information! It seems like you are referring to a word analogy: brother is to mother as fly is to spry.
To explain the analogy, the relationship between "brother" and "mother" is that "mother" is a term for a female parent, while "brother" is a term for a male sibling. So, the relationship here is based on gender.
Applying the same pattern of reasoning to the other half of the analogy, "fly" is an insect, and we are looking for a word that represents a male counterpart or synonym for an insect. The word "spry" fits this pattern because it means lively, agile, or brisk, which can be associated with the movement of a flying insect.
Therefore, the word "spry" is the answer to the analogy brother:mother::fly:?. It's great that you found this site helpful in discovering the word!