If I can still find my poems I'll just give it to you. Does the other member used to be the lead vocal just for a particular song?
well, we kinda agree that some of the songs will be sang by me and the other songs will be sang by her...
Right, Because voice is a one of the musical instrument that the band have. For every song you have to listen which voice will be suitable. So all the members should sing it. And you and your members should decide. I remember one my favorite band is the Bee Gees, they usually decide which voice would be suitable for a certain song. That's why the melody sounds good.