Noticed in the trivia for AG155 that Officer Jenny's voice actress was different and uncredited.
http://bulbapedia.bulbagarden.net/wiki/AG155#Trivia

Did some searching and it's quite possible the voice is Maya Rosewood.

http://www.imdb.com/name/nm2288713/

I know imdb isn't the most trustworthy source but since there's limited acting credits on this profile it could be genuine.

Hope this helps the bulbapedia editors