I watched the first two from Group A (like you said), and then "I Don't Believe You" and "Make You Feel My Love" from Group B.
Here's the thing: she's got talent, and a lot of it, but if she wants to make a career out of this, then she needs to start distancing herself from inevitable comparisons. If she covers another Kelly Clarkson song, or a song from another American Idol star, then I think it will be hard for people to see her as anything more than American Idol material. If she covers Kelly Clarkson, people will compare her to Kelly Clarkson. This shouldn't happen, in my opinion, because it will be hard for her to stand out on her own.
On the way to writing her own songs, it will be good to continue doing covers, but I think that at this point she should start branching out from the typical "great young female voice genre", so that she doesn't become type-casted and pigeon-holed into that genre before it's too late. This is why I was particularly interested in listening to the Dylan cover, to see what she could do with it. It was good.
...so...
I was going to say "Your Song", by Elton John, but I decided against it, since there might be too many people who might look down on her singing it, since it's sort of been unofficially retired since he performed it at Diana's funeral. Instead, I'll say "Landslide", by Fleetwood Mac. Given that Stevie Nick's voice is sort of raspy, while Era's is very smooth, there is enough difference that immediate comparisons wouldn't be drawn, but people would appreciate Era's voice more for what it is, and how she might be able to transform the well-known song. Also, the vocal range is very similar to what it seems Era has fun performing with, which would further allow her to "make it her own", and stand out in that way, without even knowing she's doing it.
So, I guess that would be my suggestion. At this point, she should probably think about starting to distance herself from the American Idol stars, and find a song that will allow her unique voice to be heard and appreciated, and I think "Landslide" will give her that opportunity.