This was briefly mentioned in one of the other threads. It seems like ISU is not looking at that option at all. It may be that she's not interested in a fifth year of school, or maybe it's because with all the backcourt players coming in next year she's needed more this year than in a hypothetical fifth season.
One important note: to get a medical hardship, she can't compete in more than 30% of a team's scheduled games, and she cannot play in the second half of the season.
The 30% calculation is based on scheduled games (one for conf tournament, 0 for other postseason games). For ISU, that's 30 games (29 regular season plus 1 for Big 12 Tourney) * 30% = 9 games. She's at 4 games, so that's not an issue.
I'm unclear whether the "second half" rule is also set at 30 games or includes all actual games played. Either way, ISU is only guaranteed 30 games, so she risks losing the hardship option if she plays in game 16 or later. Game 16 is @ OSU next Sunday, so if she plays in that game or later, she's not getting a medical redshirt.