Wow, I'm so happy to hear that Maddie is doing so much better - what a relief for you!
I hope your mother continues to heal well, give her all our best!
As to the spaying - I can sympathize with your nervousness. I'll be a wreck when Tia goes in, but the good news is, it's what is best for their health and Yorkies get spayed every day with no problems at all. Try to relax and make sure your vet calls you with updates...and make sure to keep US updated too!