She wants to marry a kaafir on paper only

Firstly: 

We ask Allaah to guide you and make you independent of means by that which He has permitted so that you will have no need of that which He has forbidden, and by means of His bounty alone.  

Secondly: 

Your question implies that currently you are not wearing hijab, for fear of being fired from your work. We will never advise you to do anything but that which we would want for our own wives, sisters and daughters. No matter what the situation, as you say, the hijab is an important matter. It is the symbol of the believing woman and the sign of her modesty and chastity. It is not permissible to neglect it on the grounds of seeking provision, which Allaah has guaranteed to everyone, and has promised to give more to those who obey Him and seek His pleasure. Allaah says (interpretation of the meaning): 

“And in the heaven is your provision, and that which you are promised”

[al-Dhaariyaat 51:22]

And Allaah says (interpretation of the meaning): 

“And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty).

3. And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allaah, then He will suffice him. Verily, Allaah will accomplish his purpose. Indeed Allaah has set a measure for all things”

[al-Talaaq 65:2-3]

So have certain faith and trust in Allaah, and be certain that your provision will not cease even if you wear hijab, rather we hope that this will bring a great relief and great provision as Allaah has promised. It is narrated in a saheeh report that our Prophet (peace and blessings of Allaah be upon him) said: “Whoever gives up something for the sake of Allaah, Allaah will compensate him with something better than it.” Classed as saheeh by al-Albaani in Hijaab al-Mar’ah al-Muslimah. 

So wear your hijab and seek permissible work in which there is no free mixing with men, and Allaah will compensate you with good, for all things are in His hand, and His bounty is great, may He be glorified and exalted. 

See also question no. 6666. 

Thirdly: 

It is not permissible for a Muslim woman to marry a non-Muslim, no matter what the reasons, even if that is only on paper as you say. Marriage is a serious matter and is to be taken seriously, regardless of how it is done. There is no such thing as marriage on paper only, as some people think, rather there is binding marriage. If it fulfils the conditions then it is valid and if it does not fulfil the conditions then it is a haraam marriage and it is not permissible for anyone to do it. 

Allaah says (interpretation of the meaning): 

“And give not (your daughters) in marriage to Al‑Mushrikoon (polytheists) till they believe (in Allaah Alone) and verily, a believing slave is better than a (free) Mushrik (idolater), even though he pleases you. Those (Al-Mushrikoon) invite you to the Fire, but Allaah invites (you) to Paradise and forgiveness by His Leave, and makes His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) clear to mankind that they may remember”

[al-Baqarah 2:221]

“then if you ascertain that they are true believers send them not back to the disbelievers. They are not lawful (wives) for the disbelievers nor are the disbelievers lawful (husbands) for them”

[al-Mumtahanah 60:10]

Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said: The Muslims are unanimously agreed that a kaafir cannot inherit from a Muslim and a kaafir man cannot marry a Muslim woman. End quote from al-Fataawa al-Kubra (3/130) 

Once again we refer to the matter of provision (rizq) – as marriage comes under the general heading of provision. One of the greatest means of attaining provision is obedience to Allaah, may He be exalted. It is strange that people try to attain provision by disobeying Allaah. This is more likely to close the door to provision; even if it is open, this will cause a person to get carried away (and he will end up in Hellfire) –  we ask Allaah to keep us safe and sound. 

There follows an important hadeeth which will increase us in faith and certain belief that provision comes through obedience to Allaah. The Prophet (peace and blessings of Allaah be upon him) said: “The Holy Spirit (Jibreel) has inspired to me that no soul will die until it has completed its appointed term and received its provision in full, so fear Allaah and do not be desperate in seeking provision, and no one of you should be tempted to seek provision by means of committing sin if it is slow in coming to him, for that which is with Allaah can only be attained by obeying Him.” Narrated by Abu Na’eem in al-Hilyah; classed as saheeh by al-Albaani in Saheeh al-Jaami’, no. 2085. 

Do not pay any attention to the looks and comments of others, for their words do not in fact cause any harm or benefit. Late marriage may be for a good purpose willed by Allaah; we do not know where goodness lies. So delegate your affairs to Allaah, may He be exalted, and spend your time in doing good deeds and expiating bad deeds, for the appointed time will soon come, the Day on which the victors will attain victory and the losers will incur loss. 

“And whoever is removed away from the Fire and admitted to Paradise, he indeed is successful. The life of this world is only the enjoyment of deception (a deceiving thing)”

[Aal ‘Imraan 3:185]

How many married woman has Allaah blessed with children and wealth, but they will be driven to the Fire on that Day. 

How many women do not attain wealth or find a husband, but they will be in the highest parts of Paradise. 

Have faith, obey Allaah and remain chaste, for this world is transient and fleeting. 

“Verily, the home of the Hereafter ___ that is the life indeed (i.e. the eternal life that will never end), if they but knew”

[al-‘Ankaboot 29:64]

May Allaah help us and you to obey Him and seek His pleasure. 

And Allaah knows best.