Have you tried putting feeder insects in smooth sided bowl and placing her next to it? Put lots in so they're all running around, and this usually gets a frog's attention. The bowl should be just deep enough that bugs can't easily get out. Cat food dishes work well. Half bury it in substrate so she can see in. If she hops away, gently put her back, unless she appears to see them but not care. In that case, leave them for a bit with a carrot chip to snack on, and hopefully she'll go for them at her leisure. Don't put her inside the bowl, she'll get in there herself when she gets to eating.
My Banjo went thru a phase during and after growth spurt where she just didn't want anything. It worried me like crazy but eventually she went back to diving on anything offered. I hope this helps.