Helen had left her own phone back at that apartment. It would have been easy for Paris to track her with it when he came back (assuming, he was smart enough to try and track her). Everything from before all this started had been lost. Phone numbers, addresses.
Helen just stood there crying into his chest for a few minutes. It's all she knew what to do right now. She had no where to go. Everything was gone. Her life was completely flipped around.
When she finally gained enough control over herself she just stayed there in his arms. It was the only safe place she knew right now. And with Achilles guarding somewhere nearby she felt safer than she had in a long time. When she spoke her voice was quiet. "I'm sorry," she said simply. "I don't know what happened. I was here and then I wasn't and the next thing I knew he was there and I couldn't get away."