But Ms Isaac this afternoon said her appointment was about improving educational outcomes for disadvantaged New Zealand children.
She denied it was politically motivated.
"I would dispute that. I'm not an ideologue. I'm interested in what works. I'm interested in sound public policy that does work and in this case I'm interested in reducing educational underachievement.
"It's not about politics, it's about New Zealand children."
Ms Isaac said she had spent nine years on school boards and many more years shaping public policy.
"I didn't come down in the last shower... I know how this works."
The other five members of the committee will be selected by Education Minister Hekia Parata.
President of the Post-Primary Teachers Association Robin Duff said the appointment of Ms Isaac "brings our worst suspicions about this ... that it is clearly ideologically driven, rather than research and evidence-based driven".
"The evidence overseas is overwhelmingly that these [charter schools] are making little difference and in many cases are actually making things worse," Mr Duff told Radio New Zealand.
Mr Duff said the committee overseeing the trial was a "farce", and Mr Banks was not interested in consultation with people in the sector.
But Mr Banks told Radio New Zealand Ms Isaac is well respected and "loves education", having spent six years on a school board.
Labour's education spokeswoman Nanaia Mahuta said Ms Isaac's appointment was political opportunism from the Act Party.
"I see it as no surprise. She has strong linked to the Act Party and they're putting in one of their mates to push along their ideology.
"I'm sure she's capable and I'm sure the Act Party see her as capable of pushing along their policy."