Dual housed Budgie

[Pampa]

I just reserved a baby handfed budgie for my 11 year old granddaughter. She lives half time with her Dad, my son. He doesn’t want the responsibility of keeping a bird but he is fine with a bird in her bedroom when she is there and when she isn’t there the budgie would be with me. I thought this was a good idea and planned on having a cage set up at both houses. I figure raising a baby under this circumstances it would be the birds normal. The pet shop guy thought it would be too stressful. To relieve the stress we could have one cage that traveled with the budgie from house to house. What do you all think? I know the birdtricks people travel with their birds but have said it only works when the birds have been raised that way. Otherwise it was too stressful.
Any tips on adapting/training a baby to this situation. I plan on working with my Granddaughter and teaching her to train the same way that I do.