Just a warning on the "oscars". you may want to go with only 1 oscar. And you will need one heck of a filtration system for the 1. - There's some good oscar forums and websites out there. I can send you the links if you want, if you decide to go that way, or you can google. Not sure if a corner tank would be the best for them anyway at adult size.
Not sure your daughter would really love to see an oscar eating either, she doesn't look the type :D (although who knows lol) Beautiful tank and stand btw! - as to what you should do with it, as in the title of the post, You should send it to me! :D
Seriously though, you could also consider wild bettas, (if you like them) A mixed community or you seem to be leaning to cichlids. TONS of pretty ones out there that's for sure. Puffers are really quite neat too.
Betta Fish are like potato chips, it's hard to have just one!
Arm yourself with knowledge. Consider advise. Make informed decisions.