I always say trust your gut on it...where to draw the line between making progress and just letting them be happy carefree kids. Some kids respond very well to therapy, some hate it and treat it like a punishment. Most in my opinion fall in between somewhere...my son, he's 6, has been to several different speech therapist and hates them all with a passion. We cut back on that no progress and he genuinely treats it like torture would rather see him happy and smiling at the park for FREE lol 😂...now occupational he loves and has made a lot of progress on to me worth it. You really have to go with your gut and kind of drown out all the criticism...you know your kid best.

Yes it is a gut check situation. Back in early days we went from therapy 2 hours a week to 4 and I thought how on earth would we find that time. Then I blinked and we were at 20-25 hours a week. It all depends on the child, the family, the therapists being a fit, and I say that not to overwhelm but to say that there is not a magic number.
Our sons behavioral ped said there is data/research around preschool/kingergarten ages benefitting from 20 hrs a week including ABA. As the child gets older things change but there also isnt the reaearch and data. She also said more therapy does not equal more progress. Sometimes the same child will flourish with 3-5 hours a week but crash at 10 or more. Therapy is just that, therapy. And she also pointed out to always bring in the parents. No one us helping their child if they are burnt out all the time. (We prob need to take a mulligan for 2020!)
You only know by feeling things out and realizing along the way development is just that: a constantly changing growing thing.
What I learned more than anything was this: trust your gut. Even when you wonder if you even have a gut instinct anymore, you do. You know. Its there. Listen to your child and watch them learn and grow. Some therapies or even therapists my son was so averse and negative. At first I thought time would fix it but eventually saw it was he didnt like the therapist. And that’s OK!

Autism = Therapy

Because there is “no cure” (sarcasm, I think there is!), it’s the only thing they think that helps. And to be honest therapy does help 95% of kids. When you get a chance to see the incredibly gifted therapist do their thing it’s actually quite amazing and fast paced. My son was one of the 5% that didn’t get much from it. But in the beginning (I’m dating myself right now having started the autism journey back in 2002 with my daughter), when therapy was a medical only thing and schools weren’t employing therapists in-school the co-pays I paid for two kids BOTH getting PT/ OT/ and speech was a monthly amount that was greater than my monthly mortgage payments! But to answer your question, when is too much? It’s hectic in the beginning because they are trying to get the process down. I think it’s a very valid question to ask the next logical question...can too much create a bad reaction with your kid? That’s child dependent, some kids enjoy the therapy experience. Some start to reject it, you need to monitor that and if you start to see your child burning out slow it down. Stay on this site long enough and you hear story after story of great incredible parents having to tell people and school districts to slow down or else!
It’s part of being your kids advocate. Being too nice is a common and regretted mistake.

I understand where you are.It’s hard to say—it can be different for each family. My son at the age of 1 1/2 was getting ABA/ parent training for 1 1/2 hours two times per week. We were also having speech once a week and OT once a week. He had a huge need for everything he was getting and I have to admit it was a tough schedule to keep as life outside therapies keeps moving. At your daughters age, most of the therapy is though play I believe so I don’t think it would be too burdensome on her? Only you can really be the judge of that.

If she does end up needing additional therapies, perhaps you could see if they can do tandem services where maybe speech’ and OT happen at the same time? I have heard of it being done and may be helpful in your situation.