I took my little Milli into the vet this morning to get spayed, microchipped, and have 2 baby teeth pulled

I choked back tears as I left her with the vet tech, but I know it's the best thing to do for her, and that I'm being responsible in doing so, but I still feel bad about putting her through the surgery. I remember how weak Emma was when she came home, and Milli's smaller than Emma was at 4 lbs. this morning.
I discussed everything with the vet tech, (meds, timing, etc.) and talked to her about the doctor that would be doing the surgery, and how things would go. I took her to the vet I'm most comfortable with for this type of thing, but it still makes me uneasy to leave my little "Millipede".
Emma was really sad to be missing her fursister when I came home-she was barking like crazy, and I could tell she had been hanging around Milli's pen and looking for her. The pee pads and blankets nearby were all messed up, and she didn't play with any of her toys like she usually does while I was out.
I'm off work today, which I think is almost worse than being at work-at least working takes my mind off things for awhile.