My wife is worried about conceiving a child. We have been married for 18 months now. She is reciting the du'a made by Hazrat Zakaryia for the child, after isha every day. She is also praying Salat Hajat every other day, and recites Sura Yasin after Fajr prayer every day. She wanted to ask if you can suggest some other Dua for her.
Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Reassure your wife and tell her that she should not get worried and troubled as everything is in the Hand of Allah and whatever Allah has predestined will undoubtedly take place. She should be patient, approach Allah, ask Him forgiveness, abide by His orders and supplicate Him. Indeed Allah does not turndown the supplications of those who insist on Him. Allah Says (Interpretation of meaning): (And your Lord said: "Invoke Me, [i.e. believe in My Oneness (Islâmic Monotheism)] (and ask Me for anything) I will respond to your (invocation). Verily! Those who scorn My worship [i.e. do not invoke Me, and do not believe in My Oneness, (Islâmic Monotheism)] they will surely enter Hell in humiliation! ). [40:60].
Allah also Says (Interpretation of meaning): (And when My slaves ask you (O Muhammad) concerning Me, then (answer them), I am indeed near (to them by My Knowledge). I respond to the invocations of the supplicant when he calls on Me (without any mediator or intercessor). So let them obey Me and believe in Me, so that they may be led aright). [2:186].
Allah will respond to her invocations and give her satisfaction, Insha Allah. In addition, she should know that the period you mentioned is very short and that not becoming pregnant in such a period should not be a cause for worry. Countless people have waited for years and years before getting children and at last Allah gave them what they desired.
As for continuing to read Surah "Ya'sin" daily, it was not reported in a sound Hadith from the Prophet Muhammad (Blessings and peace of Allah be upon him). So she should leave it and instead read whatever she can from the Qur'an as a whole, as Qur'an is a blessing and a cure.
Allah knows best.
You can search for fatwa through many choices