Personally I'd suggest that was more physics than chemistry?, as her research sounds as well - 'developing virus detection techniques using nano-technology' - doesn't sound very 'chemistry' to me, although presumably the team is from multiple disciplines?.
Unfortunately, the phrase "chemical engineer" was assigned to the people who calculate the mass flows and heat flows in a chemical manufacturing process. Assuming the word "engineer" is based on ‘contrive/devise’, there are a whole lot of chemists contriving/devising solutions to many of the world's problems.
If the expectations of your daughter's chemical career (and all chemists) is to simply design/make/analize/quantify more (new/different) chemicals, the there would be no economic benefit from the chemical industry. Ultimately, chemicals must be useful. Chemicals that drive the success of the industry solve problems outside of the chemical industry.
Chemicals that are only raw materials or intermediates to make other chemicals are important but not known outside of the chemical industry.
Many students of chemistry tend to hate the topic, physical chemistry, but that is simply understanding properties and behaviors of chemicals. Most research in chemistry is associated with finding new uses (new markets) for existing chemicals and the chemists who understand physical chemistry the best tend to be the winners in that arena. These "industrial chemists" or "applications chemists" are the people who eventually become New Business Development Managers and business leaders that know how to evolve.
Now back to the question of over-specialization...
I have worked in the chemical industry for 30+ years - solving engineering problems with chemicals and tweaking chemicals and formulations to better solve engineering problems. I have researched and developed a solid understanding of more than a hundred specific opportunities to the point I can have an interesting conversation with technical experts and teach them fine points of the role chemicals play in their process/product. I have been described as "a specialist at being a generalist" which is a nice way of being called a know-it-all.
Deciding what is and what is not chemistry is a useless question. Chemistry has been described as "the central science" for more than 40 years (
https://en.m.wikipedia.org/wiki/The_central_science). If successful, she will see the edge of many different industries before her ride is over. Hopefully, she will learn from each view, but be willing to turn away to embrace a new opportunity.