Yes, we've been your shoes. Unfortunately, not all professionals can give you a definitive answer.
On the topic of meds: I didn't think I would resort to meds for my son, but finally did at age 6 to try to help his focus; then a year later his anxiety got so bad we tried Zoloft which did help. Then his behavior got so bad hitting and breakdowns, we finally tried Risperdal. He's been on Risperdal for 1 1/2 years now and there has been a BIG improvement. I do hope to cut back on the drug as he matures (he's 9 now). We had also tried Focalin initially but my son did not do well on it.
On the topic of a label: Nobody wants their child labeled! I don't buy into Autism being the new hot label that parents want their child to have. That is absurd!
I'll tell you what our Dr. told us when we were going thru evaluations and couldn't get any answers: one person can say he has a language delay, another can say he has attention problems, another can say he has sensory issues, another can say he has motor skills delays, another can say....... (you get the idea), but it comes down to putting all these things together and making a determination that the child is on the spectrum.
The spectrum is extremely broad - it has become a catch all, but I believe that is because parents want answers to help their child and doctors can't give all the answers.
We have gotten a dx. of autism now at age 9. No surprise, we were not told anything that we didn't already know. We were not enlightened in any way. We did not have any closure or satisfaction from it. It is just what it is. We will not now do anything different from what were are already doing. BUT, it was a long and hard road getting to where we are now.
If there is any advice I can give you it is to take action with your daughter by getting her the speech and language therapy she needs. If she needs OT, get that also. Search for proper school settings to fit her needs. (when people or doctors would tell me that a few years ago, I didn't know what in the world they meant by the "right school") We did find the right school eventually - it is a private school; low student/teacher ratio; very hands on teaching, the school allows all private therapists to come on premises, they allow student aids/shadows, they allow the kids time to chill if the class gets overwelming. Kids with attention decifits and learning differences need that low ratio and time to be able to chilll out if necessary.
I know from experience none of this is as easy as me just saying it.
Good Luck to you and big hugs.