I want to note that her being an Ari6 does not fit the backstory that is given for Josephine: She is a farmer's daughter that hates Talons and probably wields her murdered father's firearm-weapon from her youngest years on.Gazetteer 3 (2003)
Pg. 26 Josephine Chantreaux can’t qualify for the Pistoleer prestige class as she is a 4th level Aristocrat with a BAB +3 only. Ignore this PrC. (Errata)
I say changing Ari4/Pis2 to Ftr4/Pis2 fits her much better.
Even better would be Swashbuckler2/Ftr2/Pistoleer2 which gives her Diplomacy as a class skill, as she is noted for her skills in diplomacy. Or you could give her the dabbler feat to get it as a class skill.