Sudden windfalls, like an inheritance, are seen in Vedic astrology primarily by the 8th house. The 8th house can bring sudden and dramatic changes, for the better or worse. It's the 2nd house (income) from the 7th house (others) so it's the house of other people's money in the form of inheritance, insurance policies, grants etc.
This is the chart of a woman who recently received quite a large inheritance in the form of several homes of a family member who passed away. She suddenly learned that her and her husband were the rightful heirs in mid January. This was her Mercury-Mercury-Jupiter dasha. Notice how Mercury is the 8th lord, and exalted in its own sign of Virgo. For Aquarius lagna, Jupiter owns two houses of wealth, the 2nd and the 11th, and in this case aspects Mercury very closely. This combination of the 5th and 8th lord Mercury, with Jupiter forms multiple dana or wealth producing yogas. This became activated during her Mercury-Mercury-Jupiter dasha which went from November 5, 2006 until March 2, 2007.
From the Moon, or chandra lagna, Mercury is aspected by the 8th lord Mars and conjunct the Moon, 11th lord of gains. This again reinforces the strength of her Mercury dasha to bring wealth through inheritance.
In the Navamsha chart Mercury is again exalted in Virgo, which further strengthens Mercury by being vargottama. It again forms a close connection with Jupiter, the sub dasha lord, who is the 9th lord of fortune. Lastly, Mercury is again connected to the 8th house by virtue of being aspected by the 8th lord, Mars.
It's also interesting to note that Jupiter is located in the 4th house and it's aspect to Mercury indicates that the inheritance was real estate related. This pattern repeats from chandra lagna as Jupiter becomes the 4th lord aspecting Mercury. Lastly, in the navamsha chart both Mercury and Jupiter are in the 4th house from the Moon.