Padded Hotsling?

Now that ds is bigger he gets red marks behind his knees with both of our hotslings, padded or not. Obviously less w/the padded, but he never seems uncomfortable at all.....
Are you using an unpadded hotsling right now?

Also, in whatever kind of sling you are using, make sure the fabric is all the way into the back of her knees, and that her bottom is really sitting down into the pouch so that it's a little lower than her knees. That helps take some of the pressure off the legs.

I do love the padded rail on the Hotslings, though!

I would say a stretch padded hotsling is what you need. I recently added a stretch sateen padded to my collection and it is very comfy, no red marks on her legs.

The slingset (see above) might be good for you too... whatever you choose, IMO, stretch is easiest on their legs.

If you are wanting to try something other then a pouch sling I would look at a ring sling. My DS loves our padded Hotsling but I love ring slings I feel like there is more I can do with them.