i have probably the stupidest question ever but maybe a breeder can answer this. my friend has a yorkie female and she is a year old now and i seen her the other day and they were asking me when they go into heat because they hadn't noticed it yet i told them the age range and then i noticed she had really big nipples and so i am wondering if she has already had a heat? is this a big factor when they have a heat is the size of the nipples? sorry guys i know dumb question lol