This time last year Rana was married to Zeedan. It's all going too fast and I think Rana is trying to convince herself that Kate was worth leaving her husband for, not to mention falling out with her family. That's why she wanted to propose and settle down with Kate as a married couple - anything less means that she threw her marriage away for nothing. She needs to see how controlling Kate is. And her mother will hit the roof when she finds out - she probably thought the cruise would "cure" her daughter if she was away from her partner for a while.