When they were younger, Roman always taught Penelope how to do new things, supported her at her volleyball games, and made time for her no matter what else he had going on. And this was back when they were only friends.
She wouldn't be the person she was today if she hadn't known him. On top of all that, he was the reason her father was still alive. He had actually died in the other world because he didn't have the referral Roman gave him.
He had always been the shelter from the storms of her life. The very thought of coming home to him had been the only reason she didn't have a total mental breakdown during their time apart.
"Don't talk like that!" Penelope snapped. "You're the best person in the whole world and you do so much for me. You are and always have been my greatest blessing and I honestly don't have words to say how happy I am to have you in my life. So don't you dare doubt yourself."