I suspect from when you say you “refrained” from sending an email for 24 hours for a 1-month friendship, you may have been contacting her too frequently for her liking. Friendships that start organically take many months or years to evolve into daily contact. Accept the outcome here and don’t continue trying for contact.

In the next friendship, try for weekly or even monthly “how are you” messages .

I would also recommend seeing if there is an in-person meeting in your area run by a group for people with autism to help you learn how to socialize.