Perfect at daycare, falls apart at home: after masking all day in a structured social environment, many girls with autism reach home depleted. Meltdowns, shutdown, or intense emotional dysregulation in the evening are the release of a day of effortful social performance.
Social scripts from TV or peers: the child repeats exact phrases from shows or other children in social contexts. This is not the same as spontaneous, flexible language. It can sound sophisticated but the underlying communication is scripted.
One all-consuming friendship rather than visible isolation. The "classic" autism pattern of obvious social isolation is often absent. A single intense, exclusive, sometimes rule-bound friendship can mask the underlying social-communication differences.
Rigid pretend-play scripts repeated identically. The same play scenario performed the same way. If another child changes the script, there is intense distress. Looks like a preference, but is rigid adherence to one acceptable version.
Sensory sensitivities — sock seams, clothing tags, certain food textures, loud sounds. Girls may become expert at avoiding triggers quietly rather than visibly melting down in public.
Intense "acceptable" special interests — horses, Disney franchises, fairies, specific animals. Because the interest is age-typical in topic, it is less visible as a restricted special interest. The intensity and exclusivity are the distinguishing features.