All the children should feel loved and praised, but making the expectations the same for every child would limit some and frustrate others. Expectations should be relative to the child's ability both physically and in terms of focus, fears, etc. For one child, showing their front support with straight arms and legs together, no belly on the bar, out of a skill may be simply just having good practice habits and not being lazy, while for another child it might be a lightbulb moment of something they've been struggling to understand in terms of body awareness. I don't think children should be praised excessively for things that are second nature to them. I'm also much more likely to praise older kids for being a good friend, for being helpful, etc, and then in the gymnastics focus on which parts were right and which ones weren't.
I sometimes see people going on and on "I'm sooooo proud of you, that was sooooo good" for something that was really just a baseline expectation of doing the task at hand. I feel in some ways this is counterproductive because it also puts a lot of pressure on children to always expect a huge reaction or to think every motion needs to make us proud or whatever. If you back off of the kids and let them "own it" they have the chance to develop independence and do things for themselves.
But of course that's within the context of a supportive environment and praise and positive motivation should always be used. But we need to establish a rapport that is not just based on praise, especially for children who are going to go on to a tougher training environment where the demands are much higher, which is likely for your daughter. She needs to learn how to have a relationship with the coach that is mutual work towards improving her physical and mental ability. But I do think at this age it is important to let them be little kids still and make sure they all feel loved, so I don't think being too tough is right. It's a balancing act. If you feel like the coach would be open to it you might want to bring a conversation around to it at the some point, I would just keep it to "I" statements and about your child. For example you could say "My daughter is learning so much and I know you are trying to prepare her for the next level. One thing I've noticed is that she responds really well to positive reinforcement because she is concerned about doing things the right way, and if she gets reinforcement then she feels more confident to move on." By approaching it this way you don't comment on her coaching, just an observation about your child.
This way the coach can prepare her without smothering her with praise, at her ability and focus level what she probably really needs is just confirmation she is working hard and doing the skills right, so she can have that confidence that she is on the right track. A nod, a thumbs up, "that's right", "you got it", "well done," etc.
