Autism, epilepsy, new diagnosis celiac disease?

My 50 yr old daughter, profound autism, epilepsy, had volvolus leading to sigmoidectomy 2024 then long recovery, has just had celiac panel done , IgA <15( normal 87-474) and IgG 164 flagged as high, and my research points to celiac disease?
She was diagnosed lactose intolerant as child after biopsy but no mention of celiac, with autism, her living in 6 bed residential carehome I know diet changes will be difficult, any suggestions?
She also has recurrent cough, upper respiratory illnesses and saw these can happen too with low iga?
Thank you