I gave a quick look-see and here are some first impressions.
I am definitely impressed by this line on their About page: "At Ethos we will never assume that you have your life together, if you won’t make that assumption about us. We are a group of imperfect people, loved by a perfect God." That is a humble position for a growing and seemingly popular church.
I'm sure you looked up their doctrinal beliefs already; I usually see it as a good thing when a church's doctrinal statement is easy to find and simple in its presentation, as this one is.
Just a quick perusal of their overall site, I did notice without looking too deeply some allusions to instructing believers in the Scriptures in their entirety. Another good thing.
They welcome the believer as well as the skeptic "and everyone in between". That could be a seeker sensitive move but given an apparent commitment to the Word, all who enter will be properly instructed.
The only catch I picked up on that leaves me some question is their stated desire to "ignite a movement". I see that as the job of the Holy Spirit alone but without inquiring further, I can let that statement go for the time being.
Overall, as you have said, she could do much worse. There are a good many in my family who, given their present church affiliations, if they were to join this church, I'd be ecstatic.
This church seems to be a very modern multi-campus kind of organization of which I am not a personal fan. I prefer the more centralized, smaller congregationally based model but that's more of a comfort thing for me.
They seem to provide plenty of links to their teachings. That would be the best resource for you to check. I think that you and I would like to see a church committed to expositional teaching but their aforementioned commitment to the entire Word is reassuring.