Achonwa did miss the first 3 games of the season, but only Michigan State would have been considered a decent opponent in those games (ND won by 19).
Braker can handle the passing aspect of what Achinwa gave the Irish. What she can't do is put it on the floor and take it to the hoop from the high post, which is what Achonwa has been doing a lot of in the tournament, especially early in games.
As an ND fan, I have considered UConn a bad matchup for the Irish this year due to the Huskies' size. Without Achonwa, Lloyd and McBride will have to shoot the lights out for the Irish to keep close and I just don't see that happening against UConn's D. Of course, Villanova did beat Georgetown many years ago ...