Kristine Krkovska, 19, broke down in tears when she was refused bail over 11 charges related to supplying drugs when she appeared in Wollongong Local Court on Friday.

Krkvoska and her mother Lida Milenkovska, 54, had their home raided on Thursday morning after Lake Illawarra police monitored their alleged sales of heroin and methylamphetamine since April as part of Strike Force Tabingo.

In documents tendered to court, police allege telephone intercepts helped investigators to identify Krkovka's regular contact with a number of associates to source drugs and on-sell to customers in the Illawarra.

Police allege buyers would call or text Krkovska with words similar to "are you good?" or "have you got" to see if she had drugs to sell them.

Krkovska allegedly tried to hide her alleged crimes through using common drug code words such as fast, slow, balls, half balls and packets.

Police further allege Krkovska changed phone numbers regularly to avoid detection and used encrypted messaging applications on her phone.

Police allege that between June and September Krkovska sold drugs to customers, mainly from her house.

Krkovska allegedly sold $350 worth of heroin, five grams and another $100 worth of meth throughout that period.

On one occasion Krkovska, allegedly speaking to a customer about the quality of heroin, told him, "I'll be honest my mum's stuff probs it's tiny bit better than mine".

On June 17, police allege a customer swapped an "eye" (meth) for "slow" (heroin) before Krkovska made another two sales that day.

Police allege on July 28 Krkovska sourced half an ounce or 14.2 grams of heroin from a supplier and arranged with another supplier to get meth on September 1 before 18 days later she organised to purchase one gram of heroin for $700.

Officers raided their Jane Avenue home just before 9.30am on Thursday where the mother and daughter were arrested and taken to Lake Illawarra police station.

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During a search of the premises, police seized methylamphetamine, ketamine, cannabis, 28g of a white powder and a small quantity of a brown substance, and mobile phones.

Krkovksa allegedly told officers, during an interview, that she assisted her mother in supplying drugs from their home.

Milenkovska was charged with 14 counts of supplying prohibited drugs, supplying prohibited drugs on an ongoing basis, being the occupier and knowingly allowing the home to be used as a drug premises and two counts of possessing prohibited drugs.

Milenkovska did not apply for bail on Friday and it was formally refused. She is expected to apply to be released on Monday.

Krkovska was charged with 11 offences, including six counts of supply prohibited drug, three counts of possess prohibited drug, supply prohibited drugs on an ongoing basis, and occupier knowingly allowing the home to be used as a drug premises.

In court on Friday, police prosecutor Sergeant Ashley Jacobs opposed Krkovska's release given she had allegedly supply drugs for an ongoing period and faced a full time custodial sentence if she was convicted.

Sgt Jacobs also said the alleged criminal conduct was "planned and organised" and the case against Krkovska was strong given the telephone intercept material.

"The accused is a 19-year-old female who has no formal income and police submit she solely relies on supplying drugs for financial support," Sgt Jacobs said. "She seems to surround herself with other individuals involved in drug supply."

Defence lawyer Greg Melrose said his client had no criminal record and suggested Krkovska's mother was the "principal offender".

He said Krkovksa had strong ties to the community as she had grown up in the Warrawong area, and her father and siblings lived close by.

Her father said his daughter could be bailed to his home where he would "impose very strict guidelines", Mr Melrose said.

Mr Melrose also suggested his client was less likely to continue allegedly supplying drugs as police had seized her phone.

Magistrate Gabriel Fleming acknowledged Krkovska was young and had no criminal history which would make her more vulnerable in custody but refused to grant bail as the allegations were serious and the prosecution case appeared strong with telephone intercepts.

The case was adjourned to November 16.