Answer, of course: enough to make trouble for the heroes, and not enough to help them. And whenever was least convenient for them.
But that's lacking in specificity.
And also she has to act to stop them just before they go to stop the other two villains. Act firmly enough that they have to kill her because they have time limits. Thus shortening their limits, cutting off possible allies, and making them face the prospect of victory followed by desperate flight.
Also, since it's multi-point-of-view, she's going to have a plot line. Revealing what she's doing along the way. At least she explained why she ignored the plotters -- they've been doing that for years, they can't be serious now (when in reality she's facing a long plot with temporal requirements) -- but she's going to have to hunt for them while they are doing their research.
At least they can pull off their rescue quickly enough to get away.
But that's lacking in specificity.
And also she has to act to stop them just before they go to stop the other two villains. Act firmly enough that they have to kill her because they have time limits. Thus shortening their limits, cutting off possible allies, and making them face the prospect of victory followed by desperate flight.
Also, since it's multi-point-of-view, she's going to have a plot line. Revealing what she's doing along the way. At least she explained why she ignored the plotters -- they've been doing that for years, they can't be serious now (when in reality she's facing a long plot with temporal requirements) -- but she's going to have to hunt for them while they are doing their research.
At least they can pull off their rescue quickly enough to get away.