My husband had a PEG tube. He was told to use VHC Boost which we ordered off of Amazon. It did not require a prescription. He could not do the hanging feeds at night because he was an aspiration risk. The dietitician told us exactly how many VHC cartons he had to PEG every day. Don't hesitate to ask for a more extensive consult with your dietician or other treatment team members. I really think you have to find what works for your sister. My husband is lactose intolerant and it required some work to find things that worked with the PEG. Our treatment team actually supports putting real food in the PEG, properly prepared, if it is important to the patient. My husband did not want to bother because he could not taste it anyway but our dietitician said to many patients it is a comfort to PEG real food. So take the lead from your sister and your treatment team but watch the calories every day. Intake matters in recovery.