Her estranged husband is battling a serious illness, owes $230,000 to the tax office and is being forced to sell his share in his barristers chambers to help repay more than half a million dollars he owes her mother, Helen Jenifer McDonald.

The couple, who were the talk of the legal fraternity when they wed in 2000, split in September last year. Ms McDonald's decision to sue her daughter and former son-in-law has exposed the myriad of financial problems facing the high-flying family.

Mr Street SC is part of a formidable legal dynasty as his father, Sir Laurence, grandfather and great-grandfather were all chief justices of NSW. He made a name for himself in 2009 when he succeeded in having the government's controversial military justice system declared unconstitutional.

But Ms McDonald has accused him of using his legal prowess to take advantage of her and is seeking $836,989.39 plus damages and costs.

Ms McDonald says she gave her former son-in-law a series of loans when he was struggling to pay the mortgage on his six-bedroom Vaucluse home. However, he has failed to repay her, she says.

In May the NSW Supreme Court gave judgment for Ms McDonald against Mr Street for $540,729.92 plus interest and some costs. Last month it made a garnishee order directing all his income to her in repayment of the debt.

On Tuesday Mr Street asked the court to stay the garnishee order pending his application to have the case moved to the Family Court.

Mr Street engaged Geoffrey Watson, SC, who recently acted as counsel assisting the Independent Commission Against Corruption inquiry into disgraced former Labor minister Eddie Obeid, to argue the garnishee order prevents him from meeting his debts to the Tax Office, paying Ms Street $1300 a month in maintenance plus her rent and bills and from meeting his own living expenses.

Mr Watson said Mr Street's practice as a barrister has already been adversely affected by his illness and his ability to earn an income will be curtailed further if he is not allowed some cash flow. Mr Street earned almost $775,000 gross income in the 2013 financial year.

Ms Street previously practised as a solicitor in mergers and acquisitions with the top tier firm now known as King & Wood Mallesons. She gave up her legal career to pursue a career as an independent singer-songwriter and ''diamond-encrusted keytar player''. She describes herself as a ''flirt'' and ''mischief maker'' on her website.

On Tuesday she told Justice Peter Hamill she has been ''on maternity leave for the last nine years'', could not afford to engage a lawyer and had been told her estranged husband would cease paying her rent, car loan and bills once their divorce was finalised next month, ''which means I'll be out on the streets''.

''I have zero dollars in my bank account. I have $3 in my wallet,'' Ms Street said.

Justice Hamill agreed to stay the garnishee orders until August 27 on the condition 50 per cent of Mr Street's income is paid to the Tax Office, some money is set aside for child support payments, and the remainder is split 70:30 between Mrs McDonald and himself. Mr Street undertook not to persuade his clients to defer or delay paying his fees and to immediately take steps to sell his shares in Seven Wentworth North chambers.

Justice Hamill also made a recommendation to the NSW Bar Association, urging it to consider providing Ms Street with pro bono legal advice. Ms Street said she intended to apply for legal aid funding but Justice Hamill said he doubted the Legal Aid Commission would fund such a case.