Yes, it is allowed. I have been a witness to this type of arrangement where the brother of a Saudi woman helped her get permission to marry a non-Saudi whose first wife was also a non-Saudi. So your Saudi should go with her brother to the emarah and apply for the marriage permission. Please note that if you choose to marry a Saudi woman, any children born to the union will not have Saudi citizenship and neither will you ever be able to obtain it. To get a better idea of the issues resulting from this marriage choice, peruse the category, Saudi Women Married To Non-Saudis/Foreigners. Best wishes!
Assalam alaikum wa rahmatullah,
I have been through your blog and found it very useful.
I have started communication with a Saudi woman, who would like me to take her as a second wife.
She is 35 years old (which I have seen makes thins easier) and her father has passed away. Although she does have a brother and mother who is supportive of her decision.
I know that the process is long but would this be even acceptable? Are non Saudi men allowed to take a Saudi woman as a second wife?