Here's the sentence I've composed. すしを買うことについて、母を尋ねる。 The meaning I intend is something like, "I'll ask my mom about buying sushi," like I'm telling my friend I'll be asking her for permission to do so. I'm unsure if this is grammatically correct in multiple respects-- can I use 買う as I did or does that require a different conjugation, like the potential, and does the について serve the purpose of blocking that whole idea off as what I will ask my mother? My logic in composing it was like, "The idea of buying sushi, regarding that, (I will) ask my mother." Thank you in advance.
I am a native speaker of Japanese but not of English. So my English may not be natural, but I hope to be helpful. Your sentence is grammatically correct and your logic is also correct. But this sentence is a bit unclear. It has several meanings. Context can change its meaning. In some context it means i’ll ask my mother when I should buy sushi. In others I’ll ask her how about buying sushi or whether I can buy sushi. So 母にすしを買っていいか聞いてみる( I’ll ask my mother whether I can buy sushi ) is more true to your intention to ask permission. And 尋ねる sounds a bit too formal like inquire in English. So 聞いてみる is more natural in this situation.