Sorry my JRT puppies are boy and girl from different litters...I lied to avoid confrontation...?

I apologize for my child-like behavior but this forum intimidates me and that makes me feel unable to be honest and therefore I can't get proper answers. I have done alot of reading and researching about owning JRT's. Now I am in this situation with the female being the second pup to arrive and being aggressive towards my male puppy. I have contacted the owner since I wrote the other question and he will take the puppy back with refund if need be..but i don't want to give up so soon..he is going to give me two more days to see if things improve between the two. I am probably going to start by feeding them seperate. Anyone that doesn't think I'm a piece of pooh for lying can now answer this question with the real information..Again I apologize..Sorry