According to sayed Sistani they cannot do a temporary marriage without the permission of the girls father. If she is independent and does not rely on her father in all cases and makes wise decisions in life that can be an exception. However when it comes to marriage you should try to seek your parents blessings as it is a major decision in life. If she does Muta with another guy without her parents permission this can potentially ruin her reputation. If her parents excuse is not justified she can have someone talk to them. Or she should do the permanent marriage and not the temporary, that way it is a solid relationship and chances of abuse would be less.