Hi, i am new to this so please bear with me. I have two yorkies, Rocko is my 3 yr old boy and ko ko is my 1 yr old girl. She weighs 4.4 lbs and he weighs 5.3 lbs. Is it safe for them to breed? She came is to heat,( i am keeping them separated). If not i plan to get her fixed. Any advise would be great thanks...