Moving to Jubail (KSA) as female

Hi @HelenD3, congratulations on the new work prospect with SADARA. I'm aware there will be millions of questions about the potential move to Saudi, let me try to answer based on what I observe here in Jubail.

No, you don't have to cover your face and depending on the situation/place - you do not need to cover your hair as well. If situations require it, a scarf wrapped loosely around your hair is acceptable. Abaya (a loose fitting robe-like attire, typically black) can be worn on top of your usual attire when you're outside.

Jubail, Khobar, Dhahran, Dammam (the Eastern Province) are quite relaxed with these because of the presence of expats working here. There are still a small group of people who would be more bothered by irregularities (not wearing Abaya, not having scarf on), and if I could suggest it is better to avoid the hassle. All in all, please be assured that clothing wise it is not going to be an issue for you here.

About women having a career, I've seen a huge change in women empowerment in the local society here in the past 5 years. I've seen the number of female employees in my company increased from 0 to ~30 within 3 years time. Most of them hold critical positions in HR, Finance, IT and Training. There are many  female expats working here as well, so it is possible for you to work. However I do not know the procedures or requirements for it.

I hope I was able to shed some light on your concerns, take care!

Greetings from Jubail
Mu Brief Introduction -i am living with family in Jubail for last thirty years . I have three boys & two daughters all married and all living in Saudia . My youngest is also elder to you .I know very well many expats who are working in SADARA   
Response to you points -(1) It is NOT a MUST to cover your face & hair but seeing the surrounding you will feel much at home when you do it like this . you will NOT feel your self stranger in this area . However there are many  western expats living in area and very soon they (plus others ) all be your friends. There is Gym for Ladies and these ladies have often coffee parties etc and meet at each other place in groups or at intercon at mutual convenience . There is a Book titled -MORALS & MANNERS IN ISLAM -A Guide to Islamic Adab by Marwan Ibrahim Qaysi . Suggest that you scan through this book to better understand local culture and background of certain norms  .
(2)SADARA hires number of ladies in its organization and has a strong Law & Contract section .Sadara may consider you on priority being spouse of one of employee .Why do not you post your CV on SADARA website after your husband has joined or even earlier ? You may be able to  get part time/ full time job in English medium western school where kids of most western expats are studying .There is no limit in doing welfare work . (3) It may be good Idea to study Basics of Islam  through books written by Muslim Scholars so you will feel more knowledgeable for this country .
Wishing all the best --- Iqbal Chaudhry

as a local ill say no, you don't have to cover your hair and face
regarding your work in a law feild, there is a department of legal affairs in almost every company you can try that
or you can try prince Mohammed bin fahad university there is a law department and it's a new major for girls in Saudi Arabia
you can try ILIE education institute and jubail university college if you are interested to teach English
and there is many international schools if you want to work with kids

good luck and welcome to Jubail