Just to review, the standard procedure for a right-handed shooter is to hold the pistol in the right hand and operate the magazine release with the thumb, catching the mag with the left hand. Most modern pistols make that fairly easy for a person with average or larger male hands.
If someone with small hands absolutely cannot get her thumb to the mag release while maintaining normal grip, what technique would you suggest?
The specific pistol in question is a Browning Buck Mark.
For every complex problem there is an answer that is clear, simple, and wrong.
—H. L. Mencken