….any professional degree is invalid if it is acquired during leave-without-pay.
It is invalid in the sense that she cannot claim continuity of service while appointed AT on qualifying RLST. As a Gr-D staff she is not entitled to get permission to acquire B.ED. degree, for her nature of service does not permit it. So she may acquire it on Leave without pay and could get its value if she is appointed as a fresher after resigning from previous service.
She can have Extraordinary Leave up to 2 years vide G.O. No. 1541-Edn (S) /21-2/77, dated 15.12.1977.