You are doing the right thing. It is better for her health. My Peanut is getting neutered next Friday. I am having the bloodwork done just to make sure everything is ok before he goes under. I spoke to the vet last week about everything and she told me they are very cautious and monitor everything, they also treat a lot of yorkies. My fear is I don't want Peanut to have any pain or be afraid when I drop him off and they have to pry him from my arms.
I have a female sheppard mix also and she was spayed 10years ago and did fine, that was before I was into the internet and reading everything I could. Does your vet accept the friends of animals of same the animals certifiates?