Her vehicle was seen crossing the centre line several times into the path of oncoming traffic.
Police found her near Tarras where she drove into a private driveway.
She showed signs of being affected by alcohol or drugs, could not speak properly and failed a breath test.
Sinclair had no explanation, police prosecutor Tim Hambleton said.
Counsel Andy Belcher asked the judge for bail for Sinclair who had an appointment with the Salvation Army today and a placement with the City Mission in Auckland next month.
He said there was a gap of a year to a year and a-half since the defendant's last drink-driving conviction and a five-year gap between the preceding two convictions.
Belcher said even though Sinclair now had a fifth conviction, she would not necessarily have to be jailed. He asked for a sentencing date and a Pact report to leave open the opportunity for her to ''get herself together and get to the Salvation Army programme''.
''I think the level of your offending and your alcohol problem has been emphasised by your presentation in court,'' Judge Crosbie said.
That Sinclair was affected by alcohol was clearly evident to court staff ''and I could smell it from the Bench''.
And when she was asked if she thought she would be able to drive yesterday, she told the judge she would not.
She was a risk to the community, and, ''on the day in question, presented a real risk''.
He had ''very strong concerns she would commit another offence if she was on bail'' Judge Crosbie said, remanding Sinclair in custody for sentence on April 24.