Here's my take - as someone who grew up with SSD (which became Deaf right, Hoh left, flux and APD) :
If she's got good speech, and is following well in a hearing environment then consider looking for options for a blended curriculum split between schools. That, or find out how to allow her to participate in various afterschool / weekend programs at the local School for the Deaf.
The early years are "easiest" - and they are *not* easy. They are exhausting. She needs to have CART in place or ASL interpreters now, even if she isn't really "ready" to use them yet. Demand at the very least CART (or TypeWell).
My parents seemed to view ASL as a "failure" - they seemed to think if they pretended I was hearing, I'd "be" hearing. I am Hoh / Deaf no amount of them thinking otherwise changed that, but it did harm my self image. It also prevented me from learning an *additional* language (ASL) that would later prove critical to my university success.
Once I got to grade 3 or 4 (in the early 80s) things became significantly more difficult - As someone stuck in an oral only environment, the in class time spent with conversations increases, and the complexity of the conversations often leave us completely lost (and sometimes we don't even know we've gotten lost - we're excellent "fill in the gap"/"guessers").
I believe the current stats are that more than 80% of students with SSD / SSHL will fail at least one grade (if it's a no-fail environment, then they'll just continue to fall behind ...which is worse because it snowballs and can have lifelong consequences in learning, careers etc).
I was mainstreamed throughout k-12 ... I didn't get much needed supports and it had deep social consequences. It also meant I had to do almost all of my learning at home after school - re-reading the textbooks for what I'd missed in class in an attempt to catch up.
In-spite of all this, I graduated from an IB program with honours - I fought like hell for every single percentage point and NO child should have to do what I did.
As soon as I graduated High School I took a lot of intensive ASL classes, started socializing with Hoh/Deaf signers, got involved with an ASL immersion summer program. It changed everything. It opened doors that had been closed. It gave me the ability to attend social gatherings and be able to fully participate.
When I attended university - I elected to have notetakers as well as ASL interpreters (I also was able to follow a little bit aurally) - this gave me complete access to the lectures, the interactions and conversations and truly made for the first "barrier free learning environment" that I'd ever had.
I have plenty of Hearing friends, my entire family is hearing and even though I don't use ASL all the time, everyday - I would never ever want to be without it. There have been so many educational, social and career opportunities that ASL has made possible.
I can't say how important learning ASL, and having a Deaf community would be for them- even if they don't attend a school for the Deaf, being connected is extremely important.
Please feel free to PM