For context I have an 11 year old DS with SEN (ADHD/not quite enough social difficulty for an ASD diagnosis/social anxiety) and a 9 year old DD who is a tiny bit immature (her best friend is a similar boy to DS).
DS has a mentor at the moment who plays with him and is helping him with turn taking etc. Today they were playing with monster trucks but I spotted a friend with a same age boy posting on FB "end of an era, we are getting rid of the toy cars".
DD plays pretend schools/hospitals/camping on her own and we've had play dates with craft/cooking though they can also be very random running around. My DN at the same age/bit older played with her dolls house though so that seems appropriate.
DS has no friends he sees outside school (he's at a specialist school which is not that far from us but other children come a long way, and friends from when he was in mainstream have all dried up). But we really need to try and get him involved in groups only I'm just not sure which of his interests (he does have others, swimming, drawing, Lego, Mario on his Switch, Minecraft) are even age appropriate.