Is my girlfriend good enough for me?

I recently met someone. Although physically she's not really my type in every other aspect she's wonderful and she is totally into me. She's attentive. She's affectionate. She's supportive. She's willing to go more than half way on everything we do together and she's already told me that she loves me. But she needs to lose 30 pounds. She even asked me and I told her. She's set the bar to lose 50 which would be great. We've only been dating for a couple of months and she's still very attentive and affectionate with me and so loving. But I want to keep my options open. I mean, I found her. What if there's someone out there who's better than she is? She's the first girl I've met that feels the way she does about me and actually SHOWS it and follows through on what she says but what if is killing me. I don't know what to do. If she were only a little prettier and skinnier she'd be perfect.