Ds is 9 months and can't roll or crawl and is getting increasingly frustrated. He tolerates tummy time but loves walking holding my hands. Now I know I shouldn't be wishing this time away where I can plonk him down and he stays put but he is just getting cross and bored. He went through a similar thing before he could sit and we got him one of those inflatable rings which was great. He can pull up using my hands but not anything else and all he wants to do is stand and walk!