Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh

In the Name of Allah, the All-Merciful, the Mercy-Giving

All praise is due to Allah. Peace and blessings be upon His Messenger Muhammad.

A Muslim is recommended to perform istikharah Prayer whenever he/she intends to do something, whether he/she has a doubt or not. Imam al-Bukhari reported on the authority of Jabir (may Allah be pleased with him) that he said, “The Messenger of Allah (peace and blessings be upon him) used to teach us istikharah as he would teach us a surah from the Quran.”

The formula of istikharah supplication intends to show one’s submission to and trust in Allah as well as one’s renouncement of power and knowledge to Him. For istikharah to be effective, a Muslim has to be sincere enough to be fully objective and unbiased to any of the available choices.

In marriage for example, after finding a spouse who fulfills the Islamic criteria, one still should give up his/her choice and pray istikharah asking Allah for guidance.

While narrating the formula of the istikharah supplication, Jabir in the above hadith said, “When anyone of you intends to do something, let him perform two rak`ahs other than obligatory prayers and let him say …”

The injunction here is obviously directed to the person who has such an intention him/herself. Therefore, the majority of scholars do not validate istikharah performed by someone on behalf of another, whereas some scholars have considered it valid but the argument they provided is quite weak.

Accordingly, you should, first, perform istikharah without prejudgment and sincerely leave the issue at the hands of Allah. Second, you should politely approach your parents and tell them that they should perform istikharah themselves and that they should observe Islamic teachings in their judgment.

As for the sign this lady claim to have found in a Quranic surah, this could be based on her own understanding and perception. A Muslim may not claim that a Quranic verse has a particular meaning or give a certain sign for something without having evidence and solid basis for this claim; otherwise, one would be attributing false meanings to the Quran, which is a great sin.

Almighty Allah knows best.