Left out

Well today it happened. A day I knew would someday come, I just didn't think it's be this soon. Today Eden got invited to a birthday party and Georgia didn't. I know it shouldn't bother me and I know the mom didn't do it on purpose. In fact I doubt it even crossed her mind. Its a little girl that lives in our neighborhood, she also is in Eden's dance class. Now I'm stuck feeling sad that Georgia is left out but also wondering how I should handle the situation. Do I take Georgia with me to take Eden to the party? Or do I leave her home with someone? I don't want to make the mom feel bad or bring an extra child she didn't expect. But they are twins. It just hurts my heart to know Georgia didn't get invited too. I know Georgia doesn't care but I do.