Is your garage at walk in level? As long as you have electricity out there you can set up a temporary sewing station. As for something to sit on, is she coming over with one of those motorized chairs? I would make the table with the machine fit that chair. Walmart sells bed risers that can be used the move a table up. If you can't manage to get her in our house you may need to go to hers. Does she want to learn how to use a machine or could you show her how to piece by hand? Not ideal but better than nothing.