While Leggs Perthes often exhibits symptoms around 7+months, hip dysplasia especially if it is mild and especially in small breeds, may not be evident until years down the road. Offa doesn't certify hips until 2yrs old.
To the OP:
I would simply ask the breeder why she is doing things the way she does. Ask if her dogs are Chic'd have they passed the minimum health testing the
www.ytca.org recommends. What are the health issues in her line(s) that she breeds.