It is narrated that Rasulullah (Sallallahu alaihi wasallam) used to say the following dua for the protection of al-Hasan and al-Husayn (His grandsons). This is a beautiful dua for protection of family members, especially our beloved children:
أَعُوذُ بِكَلِمَاتِ اللهِ التَّامَّاتِ مِنْ شَرِّ مَا خَلَقَ
A'oothu bikalimaatil-laahit-taammaati min sharri maa khalaqa.
I seek refuge in the Perfect Words of Allah from the evil of what He has created.
Recite Surah Al-Fatiha, Al ikhlaas,surah falak ,surah naas ,ayatul kursi and durood shareef as many times as u can.
بِسْمِ اللهِ الَّذِي لَا يَضُرُّ مَعَ اسْمِهِ شَيْءٌ فِي الْأَرْضِ وَلَا فِي السَّمَاءِ وَهُوَ السَّمِيعُ الْعَلِيمُ
Bismillaahil-lathee laa yadhurru ma'as-mihi shay'un fil-'ardhi wa laa fis-samaa'i wa Huwas-Samee 'ul- 'Aleem.
In the Name of Allah, Who with His Name nothing can cause harm in the earth nor in the heavens, and He is the All-Hearing, the All-Knowing.
Whoever recites this three times in the morning will not be afflicted by any calamity before evening, and whoever recites it three times in the evening will not be overtaken by any calamity before morning."
Abu Dawud 4/323, At-Tirmidhi 5/465, Ibn Majah 2/332