Hi, since you have chosen the option "Login with FB", you can't hide it. If you had chosen login with email or nickname,then you could change or not display any image. Now that you have created your account with FB user ID, I don't think you will be able to switch to other options. You may have to delete this login account in parentree and create a new one with other options.
Thank you Roshmom. You are right.
@MukeshDhanori - this is part of the default options when you login using Facebook. You can delete permissions given to Parentree, from your Facebook settings. That will deactivate your account.
And you can create a new account with a different email address.