Graendal's, I mean.

There is nothing about her plans involving Perrin that couldn't have been performed by Slayer alone. Really, the entirety of Graendal's plan was "ambush Perrin with a lot of Shadowspawn". I kid you not. The Dreamspike was not part of her original plan, that was provided to her by Moridin to help her succeed. As was Slayer. And the Children of the Light were not part of her plans either, their presence actually interfered and kept Perrin back for a long time, during which Graendal was unable to pull out her ambush.

Not saying that it wasn't a good ambush attempt, but it doesn't really fit with Graendal's established style. And why would she think this plan would work, when Perrin has access to Travelling?

The real problem is that it doesn't require Graendal's presence in any way. We've seen Slayer command Shadowspawn before. Slayer could have gone under Moridin's direct orders, he could have used the Dreamspike, he could have planned the ambush. Where was Graendal's scheming and manipulation? We don't get any evidence that she even tried to influence the proceedings between Perrin and the Children of the Light.

I just don't see why she was involved in that plot.