My teen DD is ASD and ADHD.
Life for her has been and continues to be extremely challenging. Both ADHD medication and Antidepressants/ anti anxiety meds have helped massively.
It's good that you are able to self reflect and see that this is largely down to your wish that she didn't have these challenges.
However she does have challenges, and she is struggling. So yes, even though none of us wanted this for our DCs, it's important to put our own ideals and wishes to one side and take the emotion out of it.
Side effects only happen to some and don't typically last for a long time. If you are prepared for them they seem easier to deal with if they come. They may not.
If they could genuinely help your DD and professionals have recommended it then it's actually not kind to deny them
You can try them for a period of time. It's up to her. If they improve things then great. Put aside your own feelings. You love her and want things to be better for her.
She may not need them forever
When I needed meds about ten years ago they helped massively with my own mental health. I rallied against them for ages for the same reason as you. But once I took them, I was so grateful for them. Having first hand experience of how helpful they were to me meant I was less reticent about DD being on them.
I appreciate it takes a while to come to terms with our DCs diagnosis, and accepting the fact that they have things to contend with. The last 5 years have been a huge struggle for DD and it's unfair. But it could also be a lot worse.
One thing that my DD said to me always sticks in my mind is
'It's about time you started parenting the child you have rather than the one you thought you'd have'
It's never left me and she was so right.