I did start at 4k+ rank since they put the tower. For the drop rate im not sure, I did get a dragon helm yesterday but mostly the drops are just money, lots of keys and a few normal equipments. I'll give it a week, if the girl does not drop in that time frame i'll be worried (Im basing this on my experience, 2-4 days upon opening the world and 2-3 days in between girls dropping.)