FAQ for
Starship Troopers 2: Hero of the Federation (2004) (V) More at IMDbPro »

There isn't, they are two different characters (but both played by the same actress).

There was a line that was written and shot but subsiquently cut from ST1 where Captain Deladier talks about her unmarried sister who also enlisted. When Edward Neumeier was writing ST2 it was decided it would be a cool idea if this sister was in the movie, and more so to make here an identical twin by casing Brenda Strong in the role. Some lines were written but cut before being shot making reference to this. Director, Phil Tippett has since said on several occasions that these cuts were the biggest mistake he could have possibly made as without that information some people get terribly confused by the same actress playing a different role in each film.