Daughter turning 21 within 3 months of me getting L1A approval

Within 3 months of getting her l2A she turns 21 yrs, can my daughter continue to be in the status of L2A. as long as I am on L1A? If my GC gets processed after she turns 21 would she also be eligible to be included in the familty. L1A is employee based. Does she lose her L2A status after she turns 21 and visits India and returns 3 years later? Does she have to be necessarily in the US on L2A or will she be allowed to continue her studies in India after she turns 21?