Well, what people seem to forget is that there are 128 players that start the tournament right?
Well, if Martina commits now and withdraws later, or doesn't commit and doesn't play, it doesn't make any difference.
Now, if she doesn't commit and asks later for a wildcard, true, she takes one away from an american junior but at the same time, she is letting her place to a player to enter the maindraw that otherwise would have to qualify.
In anycase, if Martina plays, through commitment or wildcard, she is taking a place of someone else, doesn't she? what difference does it make if it's a wildcard or someone who should have entered through the ranking?