A few more resources, in case they may be of help to future readers of this thread. The first 3 are informal checklists, the fourth is a summary of the DSM-5 diagnostic criteria for Autism Spectrum Disorder (ASD), which may be used informally at home as a checklist.
1-
old post with link to
article comparing gifted characteristics and ASD characteristics (Aug 2016)
2-
post with
checklist comparing gifted and ASD traits (Sept 2017,
hat tip to BananaGirl)
3-
post with link to Gifted Resource Center of New England (GRCNE) article
comparing gifted and ASD traits (Sept 2017,
hat tip to Nolepharm)
4- Summary of DSM-5 ASD diagnostic criteria
https://www.cdc.gov/ncbddd/autism/hcp-dsm.html
