What word does your mother always say?
"capable of being persuaded," 1737, from persuade + -able. Fowler recommends this over the older adjective, persuasible (late 14c.), from Latin persuasibilis "convincing, persuasive," from persuad-, past participle stem of persuadere (see persuade). This originally meant "having power to persuade," but c.1500 it also acquired the meaning "capable of being persuaded" and the older sense became obsolete.