Timeline for Receiving Diagnosis?

After over a year of obvious (to me) symptoms, we finally got my mother (76yo) to a neurologist appointment in mid June.

(Realistically, symptoms have been going on for who knows how much longer. A lot of the symptoms she’s exhibiting are how she’s always been (I have suspicions that she’s on the spectrum), but just more exaggerated than usual, plus some new, concerning behaviors that were never a thing previously.)

However, my sister forgot to bring her to the next appointment two weeks later for testing (I guess she was supposed to do some hour long test on the computer). Blood work/labs were also ordered and I can only presume those have not been done yet either.

I’m trying to figure out what it will take/how long for the doctor to reach a diagnosis. The whole situation is complicated by the fact that I live 5 hours away and I have three young children at home, so it’s not a simple thing to pop out and take her places. She is still driving, however unsafe this may be, but she is not cooperative to the idea of seeing a neurologist at all. She continually gets extremely upset and rather emotionally abusive, saying things like we think she’s crazy and we’re trying to put her in the loony bin. So I am doubtful she would go herself to these appointments. Meaning myself or my sister (an hour away, but with a full time job and kids (teen and tween) of her own) need to escort her to make sure she goes. I’m wondering if it is possible to get everything, or at least a bulk of things, done if I can manage to get down there for a few days.

I have left a message for the neurologist’s medical assistant so I can hopefully speak to someone directly. I thought maybe some people who have been through this can share their experiences with the process and timeline of the initial appointment with the neurologist through to receiving a diagnosis.