I kinda see two angles here
The first - that equates to roughly $1,000 / hr for ... talking. That's ... really difficult for me to wrap my head around as being inadequate compensation.
But
The second - I get it - talent deserves to get paid what they are worth, and for those that are serious and make it their sole career you need to pull in a lot of cash because the work comes in spurts. And that's why talent hires agents - those folks sole reason for existence is to get a better deal - with the concept being the agent gets a cut and that it nets higher for all involved. If she was trying to negotiate on her own behalf - well... you can do that, but you aren't going to get a lot of leverage.
I have no idea what is considered "fair" for voice acting - it's not exactly a new industry but it is pretty niche.