01 September 2021
Firstly, Your mother can file a divorce case under section 13 of the Hindu Marriage Act and the law applicable are same for army personals. Desertion is one of the grounds for divorce.
Talking about relief by army there is section Section 90(i) in The Army Act, 1950 that states
(i) any sum required by order of the Central Government 2 or any prescribed officers] to be paid for the maintenance of his wife or his legitimate or illegitimate child or towards the cost of any relief given by the said Government to the said wife or child.
The substantive rights of maintenance which spring from the provisions of the Hindu Marriage Act, 1955, have not been interfered with. The rights conferred on the wife/children by other laws for maintenance can be enforced not merely by moving a Civil Court but also by moving the Government under Section 90(i). The only restriction is that the deduction is to be made only by the Government as stated in Sections 25 and 90, and there can be no attachment by way of a Court decree/order. The rights and privileges of the army personnel and the rights of the wife and children have to be harmonized.