When my child turns 18, will her money be added to my account?

Hi. I assume you mean that your daughter is receiving child benefits on your account and your asking if your benefit rate will increase when she's no longer eligible for benefits. In that case, the answer's no. Child benefits paid on the account of a living parent are auxiliary (i.e. extra) benefits. Child benefits are paid in addition to the worker's benefits, not deducted from them. And, since payment of auxiliary benefits don't cause the worker's benefit rate to be reduced, the worker's rate doesn't increase if and when the auxiliary benefits stop being paid.

Best, Jerry