I am so sorry ...I can tell how much Macey meant to you and your mother and she died way too young.
You have given us an opportunity to reiterate to everyone that spaying and neutering are risky surgeries and should not be undertaken routinely and without a good reason. I am sure you were advised tht spaying was the best thing to do for Macey's long term health which is what most vets will tell you. I disagree as do most homeopathic vets.
If a decision is made that it is in the pet's best interest to alter you must choose the vet very carefully as the anesthesia is risky and the proper type needs to be used, the proper equipment needs to be used, there must be someone monitoring the vitals and the anesthesia while the doctor performs the durgery as some vets try to save costs by doing both themslves and there is no way to operate and monitor vitals too.
If you would like to learn more and want to determine if this vet may have been negligent, PM me as I would love to help you in any way I can.