Your D can always decline the offer if she should find a better job, and an offer can also be rescinded (for whatever reason). At the same time, your D may burn her bridges with the firm and even her school’s career center. D1 got her internship and job through her school’s career center. She had to sign an agreement with her school on how/when she could accept a job. If she violated their agreement then she would be banned from using her school’s service in the future. Likewise for any company that wanted to recruit on her campus. Those companies also needed to abide by the school’s rules - when they could interview/invite students for off campus interviews/how long they had to allow students to make a decision…Those agreements are to protect students as well as companies.