Schools are not required to have parental consent before beginning Tier II interventions. In my experience, it's typical for the classroom teacher to inform the parents that such interventions are taking place, but in some cases it is very informal ("I'm a little concerned with J's reading, so Ms. K is going to be working with him and three other students twice a week"). In cases where the student is struggling more, especially when it seems likely that they will eventually need special education services, meetings are more likely to be held and the RTI process explained to the parents. Still, this is not same type of formal meeting that takes place during the IEP process. Before beginning a formal evaluation (and entering Tier III/special education/IEP territory), the school is required to obtain formal, written consent from the parents. I do think it is worthwhile to speak with the teacher about the timing of the pull-outs. If the SLP is pulling children from different classes for this small group, it may be difficult to time it perfectly, but regularly missing math would not be acceptable. It sounds like a meeting to discuss scheduling, your daughter's speech goals, etc. would be helpful.