Supporters of a New Zealand woman and her young son being held in a US immigration centre are pinning their hopes on a second attempt to be released on compassionate grounds. Sarah Shaw and six-year-old Isaac were detained by the United State immigration authority - known as ICE - nearly three weeks ago after she tried to re-enter her home state of Washington from Canada without the correct documents. The mother and son have been shipped the length of the country to a facility in Texas and have been unable to be released since. Rowan Quinn reports.