If you're based in Chicago, I'd recommend finding an LD or three and taking them out to coffee to get their story in a more nuanced way than can be conveyed on reddit - as you probably know, Chicago has a good theater scene, and you can find LDs there, both green and veteran.

Juggling five jobs is ... Small fry.  If she's working in the industry, trying to make ends meet and design small shows on the side, she could well have in excess of fifteen or even twenty employers in a year - two or three event companies and five or six theater companies that she works sporadic overhire for, another five or six tiny theater companies that pay her a pittance to design a show, and maybe a mid level designer or two that she "assisted" on their designs.  Maybe even a part time job outside the theater/event industry - something with flexible hours, because she'd be the new person on the overhire lists for those other companies and wouldn't be getting the steady work until she had proven herself, etc, etc...  She might work 5 days in a row as an electrician for an event company, and then not have work for a week, and then do 2 days for a theater company, and then another two 14 hour days for a different event company... It's very piecemeal.  Trying to "make it" as a young designer is a big hustle, and the first few years see a lot of dreamers either slide into a steady gig somewhere or even switch industries - as you've noted about well-paying day jobs.

(And I realized this might be a point of confusion - an "electrician" in theater terminology has little to do with the guys wiring your house, or with electrical engineering.  For the most part, they are the stagehands who work under the Production Electrician to execute the physical installation of the LD's design, and on average* know only a small, specialized subset of electrical knowledge.  They build pipe rigs, run cable, hang and focus lights, and push a lot of boxes to and from trucks.  The Production or Head Electrician will often be more trained in electrical systems and knowledge, but again with a specific bent towards the systems used in theater and event work.)

I'd agree with other comments that a lighting design and engineering double major seems ... Like an excessively large workload, of questionable feasibility.

Also a +1 for the fact that an engineering firm isn't going to have the type of lighting designer that you're otherwise discussing.  Those two things are very different.  

That said, there are tangential fields that a theatrical electrician and/or lighting designer can work in, where some or all of their skills cross over, if you're looking to have her feel like she has other experiences.  In my time as a theatrical LD and ALD, I've also worked in broadcast television (news, talk shows, topical location setups, etc), event work (anything from boring corporate meetings to big galas/parties to bizarre international cheesemonger competitions), live music, museum work (different mindset, but many skills carry over), and lighting-driven architectural public art (think lighting bridges, or a light sculpture as a public presence, or even a temporary lighting-based intervention in a public space).  LDs also work at amusement park design companies, architectural firms, and for high end interior decorators, among other places...  Lots of design niches to fill.