Help! I had a sling that I used with my boys when they were tiny (It was the one with a double ring?) but it became too much pressure on my one shoulder as they got older. I have a 20 pound 13mo old that I would love to sling on my hip. I need to know the best sling to buy for an older baby. Can you point me in the right direction? Hopefully one that doesn't need to tie knots, because I'm not that talented!