Student loans and earnings

My client wants to pay his wife a salary from his Limited company of £7,440 for about 15 hours work a week. The wife currently receives a student maintenance loan of about £4,500 a year and a grant for her tuition fees of £3,300 a year. Is she allowed to work 15 hours a week as a student? Does she have to declare this new job/income to the student loans company and does this change the amount of the loan or grant she is entitled to get?

Lots of students have part time work in a bar or shop so there must be an answer somewhere but my searches have not come up with any answers