No, going to madinah is not a requirement of hajj. The forty namaz thing comes from some Hadith (which I have never read myself so am not sure) which basically says that if u prayed 40 namazs’ in the madinah mosque then the Prophets intercession becomes wajib on u on the day of judgement. I have nno idea if this is a strong or weak Hadith or if it really is one, because I haven’t come across it (as in I didn’t search for it but otherwise have never randomly read it).
May ALLAH make it easy for you and accept your family’s visit. If possible convey our salam to beloved:saw2: as well.
Please make sure that you know the necessary information regarding masael etc before going there, try making it a habit to make dua for longer durations. Dua is a art ,one should practice and learn it.