Summary:
According to רש"י the ל"ק maintains that מיאון is required by שידכו according to everyone; while according to the א"ד it is a dispute between שמואל and עולא. However, תוספות maintains that all agree that מיאון is required by שידכו, the ל"ק maintains that עולא argues with שמואל , while the א"ד maintains that עולא made an independent ruling and there is no argument at all.
Rather, she was Mekadaysh herself and it states that Mee’un is required - אלא דקידשה נפשה וקתני דבעיא מיאון
Summary:
שמואל requires גט ומיאון (by a קטנה שנתקדשה שלא לדעת אביה) by שידך, however by לא שידך he requires only מיאון. There is no case where עולא requires only מיאון (as stated in the משנה).