Wa 'alaykum as-salaam,
You should NOT get married without the permission of her guardian (in this case, the father) because the marriage would be void. It was narrated that ‘Aa’ishah (may Allaah be pleased with her) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: Any woman who gets married without the permission of her guardian, her marriage is invalid, her marriage is invalid, her marriage is invalid.”
(Narrated by al-Tirmidhi, 1102; Abu Dawood, 2083; Ibn Maajah, 1879. Classed as saheeh by al-Albaani in Irwa’ al-Ghaleel, 1840)
However, it is tragic that parents delay marrying of their daughters due to education and it is a great contribution to causing immorality in society. He should be advised and reminded of the warning of the Prophet (peace and blessings of Allaah be upon him) when he said: “If there comes to you one with whose character and religious commitment you are pleased, then marry (your female relative under your guardianship) to him, for if you do not do so, there will be tribulation and great mischief on earth.” Narrated by al-Tirmidhi (1084) from Abu Hurayrah; classed as hasan by al-Albaani in Saheeh al-Tirmidhi.
You should approach this proposal directly through her father and try to convince him and explain the importance of marriage, especially in today's society. If he is adamant upon refusing due to an invalid reason such as his daughter having to finish university first, then it is her right to refer this to the qaadi (Muslim judge) and he could judge based on this matter. Here in the west, she should go to the leader of an Islamic centre upon the Sunnah and they can perhaps provide a knowledgable person who can judge on this matter. However, I would suggest you trying to convince her father and make his heart at peace with it, to prevent enmity and conflicts.
As for further advice, then increase in istighfar, for Allaah says that Nūh said (interpretation of the meaning):
“I said (to them): ‘Ask forgiveness from your Lord, verily, He is Oft‑Forgiving;
‘He will send rain to you in abundance,
‘And give you increase in wealth and children, and bestow on you gardens and bestow on you rivers.’”