I had crippling social anxiety, and have never been able to pick up on signals. My dating life was a disaster in my twenties (it was nonexistent in my teens). My wife was able to straight out say, “I’m interested.” Unfortunately, our sons inherited my social anxiety and haven’t dated. I suspect they are as bad as me at picking up signals.
There have been times my wife has said, “did you see how she looked at you?” The answer was always no. Someone I dated said she had been sending signals that she was interested, and even with the benefit of hindsight I didn’t see it. There were also times I thought I saw interest when there was none, so I pretty much gave up.
I’m pretty sure my 6’3" S18 would be afraid to ask your daughter out. I say that if she really likes a guy and he’s not doing anything to take the first step and ask him out. And it’s not just the high achievers who are socially awkward. My sons and I are classic underachievers/bright slackers.