Leanne Zaloumis, who is charged with trespassing on Cowell's west London property, spoke only to confirm her name and address - Brownhill Road, Catford.
She was remanded in custody at West London Magistrates' Court for her case to be heard by a crown court judge.
More top news
Hundreds of migrants have attempted to storm Eurotunnel's French terminal in Calais in recent days, leading to long delays to services.
The driver of a lorry that killed six people in Glasgow did not disclose a previous blackout he had at work, an inquiry has heard.
A man convicted of trying to buy ricin poison from the Dark Web said he was inspired by the hit television series Breaking Bad.