Three things which would fix Illaoi (no stat nerfs)

The main problem with her is how inescapable she is if she lands that one E. It gives her huge lane advantage as you have to juggle farming, killing the tents, not getting killed by Illaoi and not getting killed by her tents.

To fix this:

1. Leaving the zone ends the curse, instead of resulting in tents spawning.
2. Tents take one hit to kill at all times (including her ult). Alternatively, as someone else has suggested, the tents spawned during her ult take one hit to kill, whilst all others take two as normal.
3. Tents supply more gold (10g?) when killed.

The solves the issue of not being able to escape. Leaving the zone surrenders some lane advantage to Illaoi at a cost of ending the curse.

If tents do spawn, one hit should be enough to kill them. They don't need to take AOE damage like Heimer's turrets, but the point is that if you're going to attack a tent, you're going to get rid of it. Requiring two hits takes just a little bit too much time and gives Illaoi a huge advantage.

Finally, the 5g you get from killing tents just isn't enough. If your spirit is taken, the amount of farm you surrender whilst dealing with it, is huge. This would soften the blow slightly.

These changes would allow all her stats to be left as they are, whilst giving the opponent a bit more counter play. As it stands, the only counter play someone has is "dodge her E".