The person was a 2.5 last year and is still a 2.5 this year? That's pretty sad.
Well, she's on the team and the captain has to play her somewhere to keep her happy (probably a friend of hers). A lot of times, none of the women on the team want to play singles. From the opposing captain's point of view the solution is to play her where no one else wants to play. Not really fair to you, but that's the breaks. Go have fun in your next match.