Share of daughter's daughter in ancestral property in 1974?

Question - What was the share of daughter’s daughter in ancestral property in 1974?

Facts:

F (Father -died in 1960)

Heirs:

M (Mother – died in 1972)

S1, S2 , S3, S4, S5, S6 (6 Sons)

D1 (Died in 1974), D2, D3 (3 Daughters)

D1S1, D1S2 (2 Sons  of D1)               

D1D1, D1D2 (2 Daughters of D1)

What was the share of D1D1 in 1974?

Answer –

First, we need to determine daughter D1’s share in ancestral property:

1.       Before Amendment of 2005, daughters did not get coparcener’s share and were only entitled to share in Father (+ Mother)’s share. Therefore, for determining their share, we need to know notional share of Father F at time of his death.

2.       D1’s share in F’s share:

At the time of death of Father F, his “notional” share was 1/8 (Everyone of Six sons, Father & Mother had 1/8^th share)

Therefore, D1’s share after death of F was 1/10^th of 1/8 of F’s share i.e. 1/80.

D1's share in M's share:

3.       Mother M’s  share (after death of F) was  1/8 (her own share as per notional partition) + 1/80 (her share in share of her husband) i.e. 11/80

So D1’s share in M’s share (after death of M) was  1/9^th of M’s share i.e. 1/9^th of 11/80 i.e. 11/720

4.       From 1 & 2:

D1’s total share is 1/80 + 11/720 = 1/36

Now, we determine daughter’s daughter D1D1’S share out of share of D1:

5.       Now  D1D1’s share in 1974 was 1/4 of D1’s share i.e 1/4 of 1/36 = 1/144

So D1D1’s Share in ancestral property was 1/144 in 1974.

Please, correct if I am wrong.