I'd get her to the vet asap for a general check up and some tests. He needs to check out her hips, pelvis, knees, eyes, teeth and general condition. Get blood taken and send it away for PRA-prcd (genetic disease that causes blindness in Yorkies), bruscellosis and have them do a general study of blood levels to make sure that she is healthy.
Having two intact dogs live in the same house means that you have to keep TWO barriers between them when she is in heat. A solid door or wall is best, but you need another buffer between the door or wall to make sure they don't slip out. The instinctual drive to procreate is incredibly strong and you need to manage them more effectively if you don't want to sterilize them.
Get someone who has experience to help you, especially on her whelping day. Someone you can phone 24/7 if something goes wrong, even if this is your vet. It's a very stressful experience and there is a lot that can go wrong in an instant even if you are completely prepared. Start saving up for tests, food, supplies, medications, vet visits, etc. You will need a solid nest egg or budget to carry the litter through to adoption.
Good luck.
__________________ Cash & Orio  RIP Beautiful Joni  |