Okay, so I know this may be FTM paranoia, but it's been eating at me.
My 8mo refused to roll for the longest time. She finally rolled tummy to back like three times at 6 months, and never has again. She rolls tummy to back constantly and no matter how long we leave her she won't correct herself.
She started sitting at 5 months, and almost immediately showed an interest in walking. If we hold her hands she will walk (usually run) around the house. It's to the point where if we don't help her walk around she gets insanely fussy and upset. Not even a remote interest in crawling. She'll hold herself up in the crawling position but just freak out until we pick her up.

She also learned how to high five for a week a month ago, and now doesn't seem to know what I'm even asking of her when I try.

Basically I'm trying to figure out worried I should be. Sorry this is long.