Unfortunately, from the front end, users may only post status updates. Editing is not supported, as status updates are considered lightweight content types and are not intended to be editable. I do share your sentiments on this, as I've sometimes entered typos and have had to delete and recreate it. I would encourage voting on the existing feature request idea here:
I hope this helps. Let me know if you had any other questions on this.
Thank you, Jeph. That helps I hope this featured is changed, would be useful for typos!