1. On the intestate death of your friend's father, the property would devolve equally to his widow and his 3 children.
2. In other words, each person is entitled to 1/4th share in the property, I.e., 25 percent each.
3. After the death of their widowed mother, the property would devolve as follows:-
(a) If she had executed 'WILL' for her share in the property during her lifetime and after her death, the property would devolve to the beneficiary/beneficiaries in the ratio as specified in the WILL.
(b) In case she dies intestate (without executing WILL), then her share would devolve equally to all her children.