Engineering programs tend to be more rather than less intense. They are often a part of a large university. A “laid back” environment small school is less likely to be where she would find her proposed major.
Big brother/sister- you seem to be acting in a “helicopter mom” manner. Remember it is HER life and her decision. Do not presume to know enough about her to predict what she really wants. Giving her lists of schools and things she can look for is as far as you should go. She will continue to mature throughout her senior year of HS (and beyond). A large university may give her room to spread her wings and discover other facets of herself. Plus- large schools are comprised of many smaller groups, she would be among the smaller engineering one.
You can help her by taking her to visit schools. Give her our suggestions. Encourage her to discuss schools with her guidance counselor. Try to avoid letting her be too dependent on you in the college process. Be supportive of HER decisions.