my 4 month old loves her chair but is very long and weighs almost 20lb so i don't think it's safe for her anymore, especially as she is trying to sit up in it.
she wasn't comfy in a bumbo as too much of her back stuck out at the top and her little legs were a bit fat for the leg holes!
i tried an inflatable ring but she braced her legs against the sides and i think she might propel herself out.
i wondered about a beanbag of some sort but i just read a review of the doomoo and it suggested not great when babies are trying to sit as they can tip it over.
and, just to be difficult, i'm not wild about the baby walker-type gadgets as i heard they are not great for the baby's pelvis due to the position they put them in (although open to persuasion)
any suggestions? i carry her a lot in the sling but can't do it all day long.