My grandaughter is 2 years old,she has had her trach most of her young life, previous to that she was on a ventilator due to many medical problems, one of them being respitory distress.When her trach was placed we were told that the size of the trach depends on the condition that you have, also they check placement by xray to see were the trach is sitting as well. I cant answer about the amount of airleak around the trach for your grandmother other than, maybe some swelling has gone done now and its also possible that this Dr could think if she had some airexchange she may be able to talk, but not sure. I sure hope for the best for your family and wish you hope and pray that your grandmothers condition gets better. Why did she have to be trached? Prayers for your family.