iPod 4th generation

Hello, I bought my daughter an iPod touch 4th generation for Christmas.

I set up an Apple ID for her through

my family sharing service so that she could get games and use some of the services on her iPod.

When I try to sign her in to iTunes & App Store it comes up with “Your purchase could not be completed” and tells me to contact iTunes support.

I can’t get any apps. It comes up with the same message then says ‘could not sign in’

Is there an obvious reason this is happening?

many thanks for any help.