When Sissy was spayed, she was done as a first appointment, but did spend the night at the vet. She was kept in their intensive care unit because of her small size. I did visit her later in the afternoon of her surgery and it was very hard to leave her. I was at the office as soon as they opened the next day to bring her home, however.
I think you should do what you feel most comfortable with - but if you bring her home, you need to be with her. I would also make sure the vet sends home pain meds for at least a couple days.
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