Looking at the horoscope of your sister it is seen that the 7th house is ruled by Venus. Jupiter the karka for husband is in the 7th house which is not good. Venus the 7th lord is in the 10th house , but combust as it is close to the Sun. Matching of the horoscope is very important for marital happiness. Chances of marriage are after June 2017.
Blessings,
Navneet Khanna
Astrologer