I don't know why the word over is necessary. Why not I'm watching the children?
So what's the difference between
"Aie confiance en moi" and "Fais-moi confiance" are interchangeable. I would suggest that the latter is more frequent.
But as far as I remember there have been a few sentences which suggest that /avoir confiance en qqn/ would mean /to be self-confident/ e.g. je n'ai pas assez confiance en moi pour faire ca.
So, can we use this expression in two different contexts ?
You can use "Je n'ai pas assez confiance en moi pour faire ça" or "je ne me fais pas assez confiance pour faire ça".
Thank you. Let me ask a last question, why it's /assez confiance/ not /assez de confiance/. I thought:
Because "avoir confiance", like "avoir peur/faim/soif/honte/envie/besoin..." uses the noun without an article and "assez", like "plutôt/plus/très/énormément..." are adverbs modifying the whole phrase.
"To watch over" is strictly correct, and means something different from simply "to watch"; but it is less usual in modern English. In the UK we would probably prefer something like "I'll keep an eye on the children".
"Trust me, I'm keeping an eye on the children." is accepted.