kids don't like my kid

so my 4.5 year old daughter has a speech issue where she doesn't always understand things as well as other and doesn't always talk as well(she sees a speech therapist weekly) well she had some kids exclude her and call her stupid at the park I shut that down quick. but I notice it kinda hurt her feelings ☹ well now at school she has a bestie but some of the other kids still don't like my kid and she says only her bestie plays with her. but no one else likes her. Do I try and intervene or just let it go? I know it sounds a bit much but it breaks my heart seeing my little girl so sad💔