Tax on land sale

She is liable to pay capital gain tax. She may save tax by invested in bonds within 6 months or another property within 2 years.  

If it is rural agricultral land, then no need to worry, since it will not be treated as capital asset u/s 2(14).

If it is capital asset then you will be eligible for exemption u/s 54B provided

- It must be used by assessee or his parents for agricultural purpose in last 2 preceding year before the date on wich transfer take place.

- Whole of the capital gain must be used for purchasing agriculture land within 2 years from the date of transfer.

- The new asset purchased should not be sold within 3 years from the date of purchase.

- If the capital gain is not utilised within the due date of filing of return u/s 139(1) then it should be deposited into an account under capital gains account scheme (CGAS).