J.M.
if it still has crystals in it you could probably refreeze it and be okay. if you wanting to use it you can set it in a bowl of warm water to hurry along the warm up.
I would smell it, if you think it smells bad then through it out. If you don't feel totally comfortable with it then don't feel bad about tossing it. We have the general rule "if in doubt, toss it." So we probably end up throwing the remnants of more condiments out than other people.
If you tried it once, and you baby won't drink it then maybe that's your answer. Don't do that again.