Why wouldn't she? Her husband took her baby away, no doubt wasn't answering her calls and she had no idea where he'd taken her. I know first-hand what it feels like to have your husband steal your baby away. It's beyond terrifying.
So I'm sorry, I'll have to agree to disagree with all who seem to think she was wrong in going to the gym, looking for Kaine and the baby; since there was no RO in effect, I don't blame Terri one bit for doing all she could to track down her child. I don't blame her if she WAS planning on taking baby K back from Kaine. Once she was served with the RO, that's a different matter altogether. But up to that point?