These things have been explained in concrete detail by many yogas and principles by astrology.
There are some houses in the horoscope which indicate marriage and its happiness.
If Venus, Moon, Mercury located in the 7th house of the horoscope and the seventh house is auspicious, the marriage happens at an early age.If Jupiter is in the seventh house or Saturn is aspected on the seventh house in the ascendant, then there will be a delay in marriage and the chances of getting married are only after at least 26 years are more prevalent.
But on the contrary, if Moon and Jupiter are in conjunction with the seventh house and the lord of the seventh house is also in an auspicious state, then the marriage happens soon.If the lord of the seventh house is exalted in a horoscope and makes a conjunction with an auspicious planet, then the marriage takes place soon.
In this case, marriage can happen even before the age of 24 years.If Venus is the lord of the 7th house in the horoscope, if it is there in the seventh house and has a good relationship between the ascendant and the second house, then the marriage happens in puberty.If the relationship between the Ascendant and the lord of the seventh house is in an auspicious one, on the other hand, the situation in the Navamsa Kundli is also auspicious, if the Karkansh of the seventh house is auspicious, then marriage happens between the age of 21 to 24 years.If the lord of the seventh house is retrograde in the birth chart and Mars is in the sixth house, then there is a possibility of a person getting married at a later age or after 30 years.
If the Ascendant, seventh house, Ascendant and Venus are in the char bhava and the Moon is situated in the char sign, then there are chances of delay in marriage.When the seventh house or its lord is in relation to 6, 8, 12 house, then in such a situation the marriage is delayed.