Reference: Sharh ‘Umdatil-Fiqh – Tape No.4, Question No.58
Question: Sometimes I give charity with the intention it is on behalf of my mother, so if I told her about it, would it be considered as showing off?
Response: If you told her to reassure her and to please her, then there is no harm in that. If, however, you told her in order to boast about it, then that is not permissible.