I'm not a doctor, but I read on the AHA site that women frequently experience nausea/vomiting (more often than men
do) when having a heart attack.
If she is complaining
of chest pain also, she should receive medical attention ASAP! If it were me I'd give her an aspirin to chew on and get her to the ER. Her symptoms warrant that IMHO. If it is nothing, hurray, and the aspirin and seeing medical professionals will not hurt her, I'm certain Dr's would agree.