The truth is - my sisters and I, along with most of my 1st cousin, were not given middle names at birth. As a result, when we got married, we made our maiden name our middle name. That way, we still keep our original identity without looking too feminized (like if we didn't change our names or by hyphenating).
Dani kept this tradition with her 3 girls, and John and I decided to do the same with our daughters.
I am sure the next question is - What if you had a boy? When we have a son (I hope!), he will have a middle name. The girls' names that we considered are so unique (and very Italian) that a middle name just doesn't seem necessary. The boys' names that we like are very classic and a middle name would be very appropriate for them.
So, that's the reasoning behind our middle name decision - in case you were wondering!