The 37-year-old Nicole G. was convicted of pimping and of seriously sexually abusing a child between 2012 and 2013.
Her former boyfriend was also convicted by the Hildesheim court to four years and ten months in prison for severely sexually abusing both the woman's then 16-year-old and 11-year-old daughters - while the mother was around.
Prosecutors said the woman had advertised her older daughter on various online portals starting when the girl was 15, using fake ages, and then organized appointments with prices, according to Spiegel. She also arranged condoms and underwear for her daughter. Nicole G. then took the money herself and threatened to kick her daughter out if she didn't have sex with the johns.
The mother also encouraged her now 40-year-old ex-boyfriend, Clemens F., to rape her daughter while the girl was so drunk so that she could not fight back, according to Spiegel.
He also sexually abused the younger daughter twice, again with her mother's encouragement, prosecutors reported.
The mother had thoroughly confessed on the first day of the trial, while her former partner contested all charges, according to the Hildesheimer Allgemeine Zeitung.
The instances of abuse occurred between 2012 and 2013, but the daughters' lawyer had complained about the delay to the start of the trial since the older girl had gone to police as early as 2013.
“It is unacceptable and intolerable for the victims to have waited so long,” said their attorney Andrea Wegert.
A court spokesperson told Spiegel that the years-long gap between the initial police report and the trial was an “isolated incident”.
The daughters - now 16 and 20 - have been living apart from the mother since the older one first went to police. The younger sister lives with her father.
According to figures from the Federal Criminal Police Office (BKA), 77 minors were found to be victims of sexual exploitation in 2015, about half of whom were German. But investigators say there is a large number of unreported cases, Spiegel reports.
In total, 11,808 cases of sexual abuse of children were recorded in 2015, and the vast majority of perpetrators are people known to the children, such as family members or friends, according to experts.