If you perform in the image of, for example, a princess, then basically, "Fixies" tracks are also possible, why not. But for the princess there should be something more magical, probably, "Masha and the Bear" is more suitable than the "Fixies". The "Fixies" series has quite a heavy music for the princess. And for older children, take mixed melodies. Some can be taken from adult music, dynamic instrumentals, and some from children's music. It will be more comfortable for them, because a child in the age of eight and older tries to prove with all his/her being that he/she is already an adult. When he/she is given music from cartoons and a clown act, he/she is ready to drive both the parents and this clown out of the house, because he/she absolutely does not need all that at all.
You need to be very attentive and make sure that the children like you too, because children will start telling other children about you. The news among children travel fast. "I had a birthday party, a lady came and blew a lot of bubbles." Everything is fine, he told 25 more children at school, other places and everywhere. And then comes the nagging: "Mom, it's my birthday, I want the same as Tanya had". Therefore, children must like you, it's very important. Even more than adults like you. We adults, always think of something else. But children, when it comes to bubbles and clowns, are experts.