I Am Asking About My 80 Year Old Mother. She

I am asking about my 80 year old mother. She returned to our home a week ago after a month in the nursing home/rehab after a right total hip replacement. Since returning home, she has experienced nausea every single evening right about 5-5:30PM. She eats breakfast and some lunch without problems, but every night after supper she complains of severe nausea. No vomiting. She is moving her bowels regularly. Blood pressure well controlled with meds. We are stumped!