The only semi-feasible answer is that she is not the one who weaved the compulsion. In that case she had another female channeler at her place with the skills required to weave her super-compulsion.

I cannot fathom Graendal leaving such a potent channeler alone in her home. Many have suggested that it was Moghedien. This is even more unlikely than just some powerful darkfriend Aes Sedai. Moghedien is even more skittish than Graendal, she is the spider. She would not stick around to risk whatever plan Rand came up with when Graendal did not.

I agree that it is possible that it was someone else that weaved the compulsion and that Graendal was not there. It just doesn't make any sense.

It makes even less sense that Graendal somehow weaved the compulsion and then had it released at the moment of the balefire after she had left. As Sidious noted, the timing is absolutely improbable. Of course, this is a fantasy novel so anything is possible, but the answer that is most consistent with the WOT world is that Graendal is dead.