Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Here is an explanation concerning excellence of some Qur'anic Surahs:
- Surah of al-Sajdah: it is reported by Ahmad and al-Tirmizi from Jabir (Radiya Allahu Anhu) that, "Prophet (Sallallahu Alaihi wa Sallam) wouldn't go to sleep before he recited Surah Sajdah and Mulk" . [4873 Sahih al-Jam'i by Albani ]. This Hadith indicates excellence of the mentioned Surah. But the Hadith you mentioned in your question about Surah al-Sajdah, is not confirmed.
- Surah of al-Waqi'ah. There is a weak Hadith reported by al-Baihaqi in the branches of Faith. Ibn Masoud (Radiya Allahu Anhu) reported that the Prophet (Sallallahu Alaihi wa Sallam) said: "Whoever reads Surah al-Waqi'ah every night, poverty will not over come him" . According to Albani in his compilation of weak Hadith, it is weak.
- Surah of Yasin, several Hadith are recorded concerning this Surah. All of them are weak or fabricated. Abu Hurairah (Radiya Allahu Anhu) reported that the Prophet (Sallallahu Alaihi wa Sallam) said: "Whoever recites Yasin once, will be equal in reward as one who recites the whole Qur'an ten times" . [al-Baihaqi in the branches of Faith, Albani said: 'It is weak'.]
Another Hadith reads: "Whoever recites Yasin for the sake of Allah, all his/her previous sins will be forgiven" . [al-Baihaqi in al-Sunan, Albani said: 'It's weak'].
- Surah of Dukhan, whatever is reported considering its excellence is very weak or fabricated. It is narrated by Abu Hurairah (Radiya Allahu Anhu) that the Prophet (Sallallahu Alaihi wa Sallam) said: "Whoever recites Ha-Mim (Dukhan) in the evening, he will enter in the morning and 70 thousand angels will ask (from Allah) forgiveness for him/her" . Albani said: 'It's fabricated'.
- Surahs that start with Ha-Mim (Hawamim), considering the excellences, as far as we know there is no authentic Hadith about it. It is reported by al-Tirmizi from Abu Hurairah (Radiya Allahu Anhu) that the Messenger (Sallallahu Alaihi wa Sallam) said to him: "Whoever recites Ha-Mim (Surah of al-Mumin/Ghafir) until "wa Ilayhel-masser" and Ayat-ul-Kursi in the morning, he will be protected by them until he enters in the evening, and whosever recites them in the evening, he will be protected by them until he enters in the morning" . Albani said: 'It is weak'.
- Surah of al-A'raf, we don't find anything about its special excellence in books of Sunnah, and it is generally recommended that we take Hadith that are authentic or good.
- Surah of al-Hashr, its excellence is mentioned in the weak Hadith, reported by al-Tirmizi and Ahmad from Moaql Ibn Yasaar that the Messenger of Allah said: "Whoever says in the morning three times: 'I seek protection of Allah, the All-Hearing, the All-Knowing from the cursed Shaitan', and recites last three verses of the Surah al-Hashr, Allah will depute to him 70 thousand angels blessing him until he enters in the evening, and if he dies on that (reciting), he dies as a martyr. Whosever recites these verses in the evening he is near the same level" . Albani said: 'It's weak'.
- Surah of Fussilat and al-Rahman, also we don't find any Hadith which indicates special excellence about these two Surahs.
As a final word, there are other Hadith that show virtues of reciting some particular Surahs and verses. Al-Sheikh al-Albani (May Allah's Mercy be upon him) collected them in his sound compilation of Hadith. But since it is difficult to mention all of them we urge you to consult the above-mentioned compilation, Riyad al-Saliheen and Miskat al-Mesabih.
So we warn the respected sister to take care about the books which contain fabricated Hadith regarding the excellences of actions. It should be known it is permissible to use weak Hadith and work by it, if that weakness comes under general principles of Islam and if they are not too weak, with person's conviction that this Hadith is substitute not fixed, because that is from the excellences of the deeds.
- And what is fabricated or too weak, or what doesn't come under general principles, it is not permissible to work with it or to be used in excellences of deeds.
Allah knows best.