Starting baby on finger foods?

So my LO is 6 months I started her on purées at 4.5 months. We had pediatrician approval.

She does a great job. I also give her happy baby teething wafers and she does a great job holding them and gumming/chewing what breaks off in her mouth.

I tried to give her finger length pieces of avocado or banana and it just breaks and crumbles when she grabs it. So I’m not really sure what I should try next. Soft finger length pieces of sweet potato? Soft sautéed apple slices?

Any suggestions? I really feel she’s ready to start with something other than purées or chunky purées.