God i hate the time of the year that daisy is in heat... she is so lethargic

a couple weeks ago we thought of breeding her, but i am sure if she gets preggo, there would be complications... My sister insisted (she's the owner) on breeding her, so i have been on the hunt for a tiny tiny chihuahua stud that'll do the job, but i am just not giving up. Hopefully i can talk her out of it. I have talked to a breeder (ahem you know who you are

) and i agree that chihuahuas are hard to breed and should only be done by experienced breeders. She has a medical condition, so she CANNOT be spayed. When she turned 1 a couple years ago, we took her to the vet to get her rabies boosster shot and another, i dont remember which one. She had the shot. she collapesd, died and was ressecitated. She was gone for a good 5 mins. She cannot get vaccines, she must stay away from ANY dog that has contact with the outside world, and she cant go outside because she puts her health at risk. Anyway, she cannot be put into sedation. that is my worry, that if she cries so hard when she gets her temperature taken in her butt, i wonder how she's gonna be when she gives birth to a litter of 2-3? i am so confused. My sister's intentions are clear, as she doesnt want her to die of a tumor inside her because she is not spayed. I dont know what to do. CAn someone give me any advice if my sister does decide to breed her? any way i can try to make her comfortable. this is a pic of her. She is 7 inches at the shoulders, and is 4 1/2 yrs old.
its not letting me post a pic. Ill log off and sign in again and try again.
it says :
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