She is refusing to travel with her husband because it is too difficult for her to live in a foreign country far away from her family

If the
husband travels and wants to take his wife with him, she has to accompany
him and move with him, so long as she will be able to live a suitable life
and will not be harmed by this travelling. 

Imam Maalik
(may Allah have mercy on him) said: 

The husband
has the right to travel with his wife from one country to another, even if
she is reluctant, and he should spend on her.

End quote
from Tahdheeb al-Mudawwanah, 1/421 

Ibn Qudaamah
said in al-Mughni (8/181): 

The woman is
entitled to maintenance from her husband, provided that she make herself
completely available to her husband. If she refuses to make herself
available or her guardians prevent her from doing so, then she is not
entitled to maintenance, even if they stay together for a while. The Prophet
(blessings and peace of Allah be upon him) married ‘Aa’ishah and consummated
the marriage with her after two years, and he did not spend on her
maintenance until after he had consummated the marriage, and was not obliged
to spend on her for the time that had passed, because maintenance becomes
obligatory in return for the wife making herself available as is his right
according to the marriage contract; if this condition is met she is entitled
to it and if it is not met then she is not entitled to anything. 

If she has
made herself available in an incomplete manner, by saying: I submit myself
to you in my house and nowhere else, or in such and such a place and nowhere
else, then she is not entitled to anything, unless she stipulated that in
the marriage contract, because she has not made herself fully available as
required by the marriage contract, so she is not entitled to maintenance.
End quote. 

This right
is confirmed in your case, because you told them about that and they
agreed. 

What the
wife is required to do is to obey her husband and travel with him, and
settle with him in the country where his livelihood is, so long as she can
live a decent life there. 

She has to
try hard to be patient and adjust to the new environment in which she is
living; she can make friends with Muslim sisters and join them in doing acts
of worship and other good deeds, such as memorising Qur’an, visiting one
another, and so on. 

She should
always remember the great rights that her husband has over her and that she
is obliged to obey him and do what he tells her to do, and she should love
to accompany him and be content to live with him whatever the circumstances.
In this manner, Muslim households will be established on a foundation of
love and harmony, and the kind treatment that is expected in Islam, which
will achieve the purposes of marriage. 

It should be
noted that these negative feelings are temporary and will disappear, if
Allah wills, if she is patient, puts up with it and seeks the help of Allah,
may He be exalted, as has happened to many other women. 

The husband
has to understand that this complaint is not something felt by his wife
only; rather many women make the same complaint because of feeling isolated
and lonely. The husband has to deal with the matter in a wise and careful
manner, and do all that he can to help her to overcome this problem. He
should give her as much of his time as he can and not come back home late
after finishing work, or go out after finishing work, except for urgent
reasons. If he can take his wife with him he should do so, and he should
help her to find female friends who will help her cope with the pain of
loneliness and feeling isolated. He should asked for help from wise people
among her family who can advise and guide her, and encourage her to live in
Saudi so that she can do Hajj and ‘Umrah and pray in the Haram and so on. 

We ask Allah
to bring you together in a good way. 

And Allah knows best.