Can we claim total tuition paid if the school doesn't accept fin aid, is private, and we haven't claimed any tuition since she began in 2015?

My wife has attended cosmetology school part time to less than part time since 2015. The school doesn't accept financial aid, so we were told in the past we could not write off her tuition, even though others she's attended with have written theirs off. Is it possible to write off this tuition, and if so, can we claim all we have paid since 2015 since we've never claimed any of it up to this point?