Capital Gains

Long term capital asset means a capital asset held by an assessee for more than 36 months immediately preceding the date of its transfer.Thus , gain arisen from transfer of property before 36 month will treat as short term capital gain.

This will be treated as long term capital gain. 

Where an asset is acquired by gift or inheritance, the period of long term capital asset shall be reckoned from the date when the previous owner acquired such asset and the indexation shall be allowed accordingly from the year of acquisition by the previous owner.

So here fall back will be done- Wife holding period is derived from Husband holding period and husband holding period will be original purchase date of ancestral property.

Trust this will solve your query.