Not at all, I think they very often are opportunities to turn to God and so vehicles of grace. "God loved me so much, He gae me cancer" is a very valid turn of thought.
in your example, the benefits were that people LEARNED something. Obviously babies can't do that.
We learned nothing from Paul's "thorn". If anything, it probably prevented him to teach more (for example, he depended on secretaries to write). So, while learning from others' work is one example, it is not the only scenario. There is also a supernatural benefit that we derive from the Christian martyrs, for example, even if we are unaware of them. Likewise, a baby benefits from the prayers of the Church, because they direct the gaze of Christ toward the baby, if I may wax poetic for a minute.
Jairus's daughter did not know Jairus interceded for her.
I agree. I just hope I don't have to prove it. :)
We learned nothing from Paul's "thorn".
Well, I learned through a very concrete example that His grace is sufficient for me, and that I have no right to blame God for when I'm hurting. I've actually thought of that passage when I was tempted to sin in my mind by feeling sorry for myself, etc.
Jairus's daughter did not know Jairus interceded for her.
And I accept the daughter's excuse. See what a nice guy I am? :) I do agree that people benefit from the prayers of others. I pray for missionaries I will never meet all the time and I hope it does some good for them. So, I think I see better what you are saying.