The C/T can be involved in an IEP meeting, but not always.
You should have a copy of the IEP. An IEP has targets for your DC, actions the school are taking to help your DC achieve the targets i.e extra support from TA/Class teacher and how you will know your child has achieved the target i.e. via assessment.
The IEP should be reviewed regularly, if child has met the targets, new ones are set. If targets have not been met, then school should review why and look at using different strategies with your DC.
If your DC continues not to make progress/achieve targets, then it maybe the child has a learning need and an assessment is required by the Education Psychologist (EP). Your school should have evidence that demonstrates the child has not made progress or very little progress, despite various interventions.
I would request your DC levels and a copy of the IEP. I would also request a meeting with the SENCO and C/T to discuss the IEP and levels.
If you are still unhappy with progress your DC has made you have parental rights to request statutory assessment from your local authority (LA). To be honest in my LA it is quicker this route.
If you need support or advice contact your LA SENAR (maybe called SENAS or SEN) parent support group.
Yes a 2c in yr 4 is the same as a 2c in yr 2, sorry.