We got our G4 at the Verizon Store.  They had their Tempered Glass protector there for $25.  We have a 25% discount for accessories on our account, so only $18.75.  Had them put it on (saved myself the aggravation), and it looks/works fine.  I have a DBACases one on my Note 3, and the Verizon one seems just as good.
Also got the Incipio DualPro case - fairly thin/light, with hopefully decent protection.  With the TG protector, she should be set, without adding too much weight/bulk to the already somewhat large phone.