I've watched my DGD (20 mos.) 5 days per week since her birth. Last year we bought a playpen-type thing that comes in 8 panels of lightweight but sturdy plastic. One of the panels has a gate with a locking mechanism. The panels lock together quite tightly. We bought it when the baby had started walking and I couldn't safely leave the room to go to the bathroom or switch the laundry. We didn't end up using very long because the baby didn't like it, but it was invaluable last Christmas. We set up the tree and put the "fence" around it. I think it would be great to set up around your sewing machine and chair, especially if you use a corner and can make the fence come out from the walls on 2 sides instead of making a complete (smaller) circle. I got mine on eBay with free shipping and paid about $100 for it (look under "play pens"). I would however caution you about rotary cutter, seam rippers, needles, pins, etc. Get a small plastic box that is lockable. Kids are little monkeys and can get into mischief very quickly. Good luck! Let us know how it all works out.