Marriage, in Islam, is solemn contract. Islam lays down rules and regulations that guarantee its stability and prosperity. Among these regulations is that one should be keen to marry a righteous Muslim.

Dr. `Abdel-Ghaffar Hamed Hilal, former Dean of the Faculty of Arabic Language at Al-Azhar University, states that: “In choosing a life-time partner, people are more inclined to having preference for beauty. But at the same we notice that some people go for wealth; others prefer nobility, and some other group of people prefer the religious and righteous woman. Actually we go along with those who prefer the religious woman, as it conforms with the following command of the Prophet (peace and blessings be upon him):
“A woman is married for four things, namely her wealth, her family status, her beauty, and her religion. So you should marry the religious woman, (otherwise) you will be a loser.” (Reported by Al-Bukhari)
Concerning proposing to a lady who neglects salah, my advice is to ask her about her readiness to pray regularly. If she is really determined to pray five times a day and you come to see the fruits of your advice by seeing her observing prayers on daily basis, then go ahead with the marriage. However, if she does not respond to you and you see her always neglecting her salah, then you should drop off the idea of proposing to her.
One should search for a woman that observes salah regularly as salah is the cornerstone of Islam. It is the second pillar of Islam according to the well-known hadith:
“Islam has been built on five pillars: To bear witness that there is no god but Allah and that Muhammad is His Messenger; to perform the salah…”
Also, the Prophet (peace and blessings be upon him) is reported to have said:
“Between man and disbelief is the negligence of prayer.”
So, dear brother, it’s very important for you to show caution when choosing your future partner. You have to pay attention to her commitment to salah and other Islamic ordinances, as well as her avoidance of what Allah prohibited, so that you get the righteous wife Allah told us to get married to:
“Marry those among you who are single, or the virtuous ones among yourselves, male or female: if they are in poverty, Allah will give them means out of His grace: for Allah encompasseth all, and he knoweth all things.” (An-Nur: 32)”