Hello! My fiancé and I will be picking up our baby next month, so we are trying to prepare for her. I was looking online for crates. Our breeder says that our puppy will probably grow to be about 6 pounds (she is about 3 pounds now). We will be using the crate to potty train her and she will also be sleeping in it at night. I was looking at the Midwest crates and wasn't sure if I should get the XS (18"L x 12"W x 14"H) or S (24"L x 18"W x 19"H). Suggestions please?