dog biting and being very aggressive

Question
 I have a 7 month old yorkshire terrier, named Lily. She was very loving and adorable, I was going to have one batch of puppies, so she is not spayed. Lately within the last month she has been very aggressive to anyone who trys to get close to you or hand you the phone etc, if you are sitting down or laying down but not if you are standing up. For example last night my daughter was going to say goodbye to my husband who was sitting in his chairMy daughter  went up to my husband to give him a kiss and hug and Lily jumped up on the chair where he was sitting and came unglued. She then turned around and bite my husband in the arm and drew blood this time. Same thing if you are laying on the bed and some one enters the room she will just loss it and bite. She doesn't seem to have favorites, its just who ever is there at the time. Her barking has increasesd alot and she just seems really hyper. We all spend alot of time with her and play with her alot and we take her on walks so, If you have any suggestions I would greatly apprecaite. We really need to get ahold of this. Thanks Alot

Answer
It really sounds like the typical behavior changes of a young female as her first season approaches.  My advice is to spay her quick before it advances so far the vet will want to wait until after it is over.

Why are you thinking about one litter?  Certainly we don't need to perpetuate the nasty streak she is developing.  What makes her so special it is worth adding to the terrible problem of our over population of pets?  You might go to www.petfinder.org and see how many Yorkies are available.  Another good site is the breeding section of www.akc.org.  I spend a lot of time on the net sharing with other dog lovers.  None of them would encourage you.  Some of them feel I am too gentle on this subject.

Have you experienced going through a females season in the past?  I am in a program that requires me to keep intact females through their first season in order to evaluate them as breeding stock after their year.  It is a big hassle. I do some work with another program that is happy to have my help because I am willing to house intact puppies.  Many of their volunteers refuse.  

One more link, http://www.k9forums.com/forums/showthread.php?t=3576&highlight=pregnant  This is a discussion where somebody's female unexpectedly slipped out the door an may now be pregnant or have an infection.  I think some of the answers are overly harsh.  Many dog owners are poorly informed.  I am doing my best to help you.