This is nothing you have done. Most toddlers go through a stage like this and if it has happened to them at daycare then they can repeat it. I think you dropping to her level and immediately telling her it is not right to bite was the right thing. I would be having a word to the day care centre about the alleged biting from the little boy and see if they know anything about it. Your choice to smack or not to smack is entirely your own. It doesn't mean that you are bringing up a spoilt child if she is under control. You can try the time out corner but they recommend that you only give them a time out for how old they are so 1 y/o = 1 minute. Good luck
What Kim said. And many hugs hun.

I've found the naughty corner to be hundreds times more effective than any gentle smack we've painstakingly given. And thankfully the older she seems to get, the more of the eye to eye staring conversations seem to sink in.
Many