Turn down unpaid internship for paid internship?

My daughter was offered and accepted an unpaid internship. Immediately after accepting, she got a call to interview for a paid internship she would love. If she gets offered the paid internship, how bad would it be to turn down the unpaid internship for a better one that is paid!?

its not bad at all and is perfectly understandable.
she just needs to tell the unpaid internship sponsor that she has had a better offer. And wont be able to work for them .

My D was in this position too. But since she had gotten the internship through career services at her school, and the company recruits there every year, she felt she shouldn’t back out.