This is a mixture of BSs and A Fact:
I don't know where did these 'facts' come from, but I would say most of them are BS:
1) Mumtaz was ShahJahan's SECOND wife
" Arjumand Banu Begum was married at the age of 19, on 10 May 1612, to Prince Khurram, later known as Emperor Shah Jahan, who conferred upon her the title "Mumtaz Mahal". Though betrothed to Shah Jahan in 1607, she ultimately became his second wife in 1612 and was his favorite. " wikipedia
Shah Jahan had SEVEN wives? - NOPE He had THREE wives:
Arjumand Banu Begum aka Mumtaz Mahal
2) ShahJahan killed Mumtaz's husband:
" In 1608, Prince Khurram (Shah Jahan's birht name) was engaged to Arjumand Banu Begum (aka Mumtaz) – when they were 15 and 14 years old, respectively. But for some reason, the Prince was not married to Arjumand Banu Begum for five years, which was an unusually long engagement for the time. However, Shah Jahan married the daughter of great-grandson of Shah Ismail of Persia with whom he had a daughter, his first child. " -wikipedia
3) Yes, this is a fact...err, so what's wrong with it?
" Mumtaz Mahal died in Burhanpur in 1631 AD (1040 AH) while giving birth to her fourteenth child. She had been accompanying her husband while he was fighting a campaign in the Deccan Plateau. Apparently after her death, Shah Jahan went into secluded mourning for a year. When he appeared again, his hair had turned white, his back was bent, and his face worn." Wikipedia
4) Shah Jahan married Mumtaz's sister?
" Shah Jahan did not marry after the death of Mumtaz, definitely not the sister of Mumtaz. After Mumtaz's death, Shah Jahan was inconsolable and spent the rest of his years in mourning, and construction of Taj Mahal in her memory, as a symbol of love. Later when he died, his body was also buried beside Mumtaz in Taj Mahal. " http://www.hoaxorfact.com/