regular episodes of being in own world

I am looking for advice/guidance and insight into something new that has developed with a 7 year old girl with  autism.  She is quite often 'in her own world', laughing, giggling, talking to self etc and not really engaged with her environment and what is being said to her.  Getting her focus and attention  back s quite challenging.  Aftermovement breaks and other simialr activities, she may regain focus but then tends to go back to whatever is occupying her mind.  When asking about it, she sometimes is able to share what she is laughing about not not always.

I would like to understand this better as an education practitioner.

Thank you